fix: default client fileApi is the Nexus raw tdlm-client; tell the player when the manifest cannot be fetched

The default pointed at packages.dandanton.com/tdlm-client/latest (404), so the first-launch auto install
silently did nothing. It now points at https://maven.dandanton.com/repository/tdlm-client, and a failed or
malformed manifest shows an error and opens the import wizard (same behaviour as the Start menu install).

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

.github/workflows/gradle.yml

@@ -36,25 +36,23 @@ jobs:
         cache-jdk: true
 
     # Nest mirrors github.com/gradle/actions as actions/gradle-actions (also as gradle/actions).
-    # v5 rejects cache-provider; v6 supports it. Default on v6 is "enhanced" (commercial) —
-    # on Gitea use external and cache Gradle home with actions/cache below (org IC2/Forestry pattern).
+    # Match ForestryMC/IC2: on Gitea use cache-provider external (no setup-gradle Actions cache).
+    # Do NOT actions/cache the whole ~/.gradle/caches — that hit ~4GB here and OOM'd the
+    # Windows Docker runner on restore; siblings never cache that tree.
     - name: Setup Gradle
       uses: actions/gradle-actions/setup-gradle@v6
       with:
         cache-cleanup: never
         cache-provider: ${{ github.server_url == 'https://github.com' && 'basic' || 'external' }}
 
-    # Cache wrapper + dependency/build caches (covers what setup-gradle skips under external).
-    - name: Cache Gradle home
+    # Wrapper only (small). Dependency jars re-download when cold — same as org mod CI on Gitea.
+    - name: Cache Gradle wrapper
       uses: actions/cache@v4
       with:
         path: |
-          ~/.gradle/caches
           ~/.gradle/wrapper
           .gradle/wrapper-neo
-        key: gradle-home-${{ runner.os }}-${{ hashFiles('gradle/wrapper/gradle-wrapper.properties', 'gradle/wrapper/GradleWrapperNeo.java', '**/libs.versions.toml', '**/*.gradle.kts', '**/*.gradle') }}
-        restore-keys: |
-          gradle-home-${{ runner.os }}-
+        key: gradle-wrapper-${{ runner.os }}-${{ hashFiles('gradle/wrapper/gradle-wrapper.properties', 'gradle/wrapper/GradleWrapperNeo.java') }}
 
     # Xvfb alone is not enough: JavaFX Glass needs GTK/X11 libs or Platform.startup fails with
     # GtkPlatformFactory "Internal Error" and :HMCL:test can hang (looks like a checkstyle stall).

.github/workflows/publish-tdlm.yml

@@ -0,0 +1,249 @@
+name: Publish TDLM launcher
+
+# Builds HMCL.exe / HMCL.jar and publishes them for TDLMPack / players:
+#   1. Gitea Release assets (versioned download page)
+#   2. Gitea generic package tdlm-hmcl/latest (stable curl URLs)
+#
+# Mirrors TDLM/TDLMPack's pack.yml publish style (nest API host; Cloudflare
+# in front of git.potatolab.uk blocks Python urllib for large uploads).
+#
+# Auth (same name as TDLMPack pack.yml):
+#   secrets.TDLM_PACK_TOKEN — Gitea API token with package + release write.
+#   Prefer an *org* secret (like MAVEN_USER/MAVEN_PASSWORD) so HMCL inherits it;
+#   today it exists only as a TDLMPack *repo* secret unless promoted.
+#   Falls back to github.token when TDLM_PACK_TOKEN is unset (same-repo release;
+#   org generic packages may still need the pack token).
+
+on:
+  workflow_dispatch:
+    inputs:
+      release_tag:
+        description: "Release tag (also used as the release title). Example: 2026.11.08 or v3.dev-abc1234"
+        required: true
+        type: string
+  # Gitea records a push run whenever this file changes; without a push job the run
+  # fails with 0 jobs. Keep a no-op so the check is green; real publish stays dispatch-only.
+  push:
+    paths:
+      - '.github/workflows/publish-tdlm.yml'
+
+concurrency:
+  group: ${{ github.workflow }}
+  cancel-in-progress: false
+
+jobs:
+  noop:
+    if: ${{ github.event_name == 'push' }}
+    runs-on: ubuntu-latest
+    steps:
+      - run: echo "publish-tdlm is workflow_dispatch-only; push no-op ok"
+
+  publish:
+    if: ${{ github.event_name == 'workflow_dispatch' }}
+    runs-on: ubuntu-latest
+    timeout-minutes: 90
+    steps:
+      - uses: actions/checkout@v6
+
+      # Same caching pattern as gradle.yml / TDLM ForestryMC+IC2 setup-build.
+      - name: Set up JDK 17 + JavaFX
+        uses: actions/setup-java@v6
+        with:
+          distribution: 'liberica'
+          java-version: '17'
+          java-package: 'jdk+fx'
+          cache-jdk: true
+
+      - name: Setup Gradle
+        uses: actions/gradle-actions/setup-gradle@v6
+        with:
+          cache-cleanup: never
+          cache-provider: ${{ github.server_url == 'https://github.com' && 'basic' || 'external' }}
+
+      # Wrapper only — do not cache ~/.gradle/caches (org siblings don't; ~4GB killed Docker).
+      - name: Cache Gradle wrapper
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.gradle/wrapper
+            .gradle/wrapper-neo
+          key: gradle-wrapper-${{ runner.os }}-${{ hashFiles('gradle/wrapper/gradle-wrapper.properties', 'gradle/wrapper/GradleWrapperNeo.java') }}
+
+      - name: Cache apt packages
+        uses: actions/cache@v4
+        with:
+          path: ~/apt-cache
+          key: apt-javafx-xvfb-${{ runner.os }}-${{ runner.arch }}-1
+
+      - name: Install Xvfb and JavaFX GTK deps
+        run: |
+          pkgs='xvfb libgtk-3-0 libxtst6 libxxf86vm1 libgl1 libxi6 libx11-6 libxext6 libxrender1'
+          sudo mkdir -p /var/cache/apt/archives/partial
+          if [ -d "${HOME}/apt-cache" ] && [ -n "$(ls -A "${HOME}/apt-cache" 2>/dev/null)" ]; then
+            sudo cp -a "${HOME}/apt-cache/." /var/cache/apt/archives/
+          fi
+          sudo apt-get install -y --no-install-recommends $pkgs \
+            || { sudo apt-get update && sudo apt-get install -y --no-install-recommends $pkgs; }
+          mkdir -p "${HOME}/apt-cache"
+          cp -a /var/cache/apt/archives/*.deb "${HOME}/apt-cache/" 2>/dev/null || true
+
+
+      - name: Build executables
+        run: xvfb-run --auto-servernum ./gradlew :HMCL:makeExecutables --no-daemon --parallel
+        env:
+          JAVA_TOOL_OPTIONS: -Djava.awt.headless=true -Dprism.order=sw
+          VERSION_TYPE: unofficial
+          MICROSOFT_AUTH_ID: ${{ secrets.MICROSOFT_AUTH_ID }}
+          CURSEFORGE_API_KEY: ${{ secrets.CURSEFORGE_API_KEY }}
+
+      - name: Stage stable launcher names
+        run: |
+          set -euo pipefail
+          mkdir -p build/tdlm-hmcl
+          jar="$(ls -1 HMCL/build/libs/HMCL-*.jar | grep -v '\.sha' | head -n1)"
+          exe="$(ls -1 HMCL/build/libs/HMCL-*.exe | grep -v '\.sha' | head -n1)"
+          test -n "$jar" && test -n "$exe"
+          cp -f "$jar" build/tdlm-hmcl/HMCL.jar
+          cp -f "$exe" build/tdlm-hmcl/HMCL.exe
+          # Prefer Gradle-produced checksums when present; otherwise compute.
+          if [ -f "${jar}.sha256" ]; then cp -f "${jar}.sha256" build/tdlm-hmcl/HMCL.jar.sha256
+          else sha256sum build/tdlm-hmcl/HMCL.jar | awk '{print $1}' > build/tdlm-hmcl/HMCL.jar.sha256
+          fi
+          if [ -f "${exe}.sha256" ]; then cp -f "${exe}.sha256" build/tdlm-hmcl/HMCL.exe.sha256
+          else sha256sum build/tdlm-hmcl/HMCL.exe | awk '{print $1}' > build/tdlm-hmcl/HMCL.exe.sha256
+          fi
+          echo "STAGED_JAR=$jar" >> "$GITHUB_ENV"
+          echo "STAGED_EXE=$exe" >> "$GITHUB_ENV"
+          ls -la build/tdlm-hmcl
+
+      # Stable player/CI channel: overwritten in place under tdlm-hmcl/latest.
+      - name: Publish generic package tdlm-hmcl/latest
+        env:
+          # Same secret name as TDLM/TDLMPack pack.yml (org or repo). Not MAVEN_*.
+          TDLM_PACK_TOKEN: ${{ secrets.TDLM_PACK_TOKEN }}
+          GITHUB_TOKEN: ${{ github.token }}
+          GITEA_PACKAGE_ROOT: https://git.nest.potatolab.uk:8443/api/packages/TDLM/generic/tdlm-hmcl/latest
+        run: |
+          python3 - <<'PY'
+          import os, pathlib, urllib.error, urllib.parse, urllib.request
+          token = (os.environ.get("TDLM_PACK_TOKEN") or os.environ.get("GITHUB_TOKEN") or "").strip()
+          token_src = "TDLM_PACK_TOKEN" if os.environ.get("TDLM_PACK_TOKEN", "").strip() else "github.token"
+          if not token:
+              raise SystemExit(
+                  "Need secrets.TDLM_PACK_TOKEN (promote TDLMPack's repo secret to org, like MAVEN_*) "
+                  "or a usable github.token to publish tdlm-hmcl")
+          print("auth=" + token_src)
+          upload_root = os.environ["GITEA_PACKAGE_ROOT"].rstrip("/")
+          root = pathlib.Path("build/tdlm-hmcl")
+
+          def put(name: str, data: bytes):
+              url = upload_root + "/" + urllib.parse.quote(name, safe="")
+              request = urllib.request.Request(url, data=data, method="PUT")
+              request.add_header("Authorization", "token " + token)
+              request.add_header("Content-Type", "application/octet-stream")
+              request.add_header("User-Agent", "tdlm-hmcl-publish")
+              try:
+                  with urllib.request.urlopen(request, timeout=1800) as response:
+                      response.read()
+              except urllib.error.HTTPError as exc:
+                  raise SystemExit("HTTP %s uploading %s: %s" % (exc.code, name, exc.read()[:500]))
+
+          for path in sorted(root.iterdir()):
+              if path.is_file():
+                  put(path.name, path.read_bytes())
+                  print("PACKAGE " + path.name)
+          print("generic=" + upload_root)
+          PY
+
+      # Gitea release (versioned). Nest API avoids Cloudflare blocking large urllib uploads.
+      - name: Publish Gitea release
+        env:
+          RELEASE_TAG: ${{ inputs.release_tag }}
+          TDLM_PACK_TOKEN: ${{ secrets.TDLM_PACK_TOKEN }}
+          GITHUB_TOKEN: ${{ github.token }}
+          GITEA_API_URL: https://git.nest.potatolab.uk:8443/api/v1
+          GITEA_PACKAGE_ROOT: https://git.nest.potatolab.uk:8443/api/packages/TDLM/generic/tdlm-hmcl/latest
+          TARGET_COMMIT: ${{ github.sha }}
+        run: |
+          python3 - <<'PY'
+          import json, os, urllib.error, urllib.parse, urllib.request
+          tag = os.environ["RELEASE_TAG"].strip()
+          token = (os.environ.get("TDLM_PACK_TOKEN") or os.environ.get("GITHUB_TOKEN") or "").strip()
+          token_src = "TDLM_PACK_TOKEN" if os.environ.get("TDLM_PACK_TOKEN", "").strip() else "github.token"
+          api = os.environ["GITEA_API_URL"].rstrip("/") + "/repos/TDLM/HMCL"
+          package_root = os.environ["GITEA_PACKAGE_ROOT"].rstrip("/")
+          target = os.environ.get("TARGET_COMMIT", "main").strip() or "main"
+          if not token:
+              raise SystemExit(
+                  "Need secrets.TDLM_PACK_TOKEN (org-preferred, same as TDLMPack) or github.token")
+          print("auth=" + token_src)
+          if not tag:
+              raise SystemExit("release_tag is empty")
+
+          def call(method, path, data=None, content_type="application/json", timeout=90):
+              request = urllib.request.Request(api + path, data=data, method=method)
+              request.add_header("Authorization", "token " + token)
+              request.add_header("Accept", "application/json")
+              request.add_header("User-Agent", "tdlm-hmcl-release")
+              if data is not None and content_type:
+                  request.add_header("Content-Type", content_type)
+              try:
+                  with urllib.request.urlopen(request, timeout=timeout) as response:
+                      body = response.read()
+                      return json.loads(body) if body else {}
+              except urllib.error.HTTPError as exc:
+                  if exc.code == 404:
+                      return None
+                  detail = exc.read()[:500]
+                  raise SystemExit("HTTP %s for %s: %s" % (exc.code, path, detail))
+
+          body = (
+              "TDLM/HMCL launcher binaries for players and TDLMPack.\n\n"
+              "Stable generic (overwrite in place):\n"
+              "- %s/HMCL.exe\n"
+              "- %s/HMCL.jar\n\n"
+              "TDLMPack does not Maven-resolve this launcher; point the pack README / install docs at these URLs "
+              "instead of hand-copying exe/jar.\n"
+              "Client pack fileApi default: https://packages.dandanton.com/tdlm-client/latest\n"
+              "(Pack must publish/mirror the same layout; see docs/TDLM_CONSUME.md).\n"
+          ) % (package_root, package_root)
+
+          quoted = urllib.parse.quote(tag, safe="")
+          release = call("GET", "/releases/tags/" + quoted)
+          if release and not release.get("draft"):
+              raise SystemExit("Release tag already exists: " + tag)
+          if not release:
+              release = call("POST", "/releases", json.dumps({
+                  "tag_name": tag,
+                  "name": tag,
+                  "target_commitish": target,
+                  "draft": True,
+                  "prerelease": False,
+                  "body": body,
+              }).encode("utf-8"))
+          release_id = release["id"]
+
+          staged = [
+              ("HMCL.exe", "build/tdlm-hmcl/HMCL.exe"),
+              ("HMCL.jar", "build/tdlm-hmcl/HMCL.jar"),
+              ("HMCL.exe.sha256", "build/tdlm-hmcl/HMCL.exe.sha256"),
+              ("HMCL.jar.sha256", "build/tdlm-hmcl/HMCL.jar.sha256"),
+          ]
+          for name, path in staged:
+              if not os.path.exists(path):
+                  raise SystemExit("missing " + path)
+              for old in call("GET", "/releases/%s/assets" % release_id) or []:
+                  if old.get("name") == name:
+                      call("DELETE", "/releases/%s/assets/%s" % (release_id, old["id"]))
+              with open(path, "rb") as asset:
+                  call(
+                      "POST",
+                      "/releases/%s/assets?name=%s" % (release_id, urllib.parse.quote(name)),
+                      asset.read(),
+                      "application/octet-stream",
+                      1800,
+                  )
+              print("RELEASE asset " + name)
+          call("PATCH", "/releases/%s" % release_id, json.dumps({"draft": False}).encode("utf-8"))
+          print(release.get("html_url", "Release created"))
+          PY

HMCL/src/main/java/org/jackhuang/hmcl/Metadata.java

@@ -141,9 +141,9 @@ public final class Metadata {
         return null;
     }
 
-    /// Default client Server Modpack fileApi published by TDLMPack (Gitea generic package `latest`).
+    /// Default client Server Modpack fileApi: the Nexus raw repository `tdlm-client` read through the CDN host.
     public static final String DEFAULT_CLIENT_FILE_API =
-            "https://git.nest.potatolab.uk:8443/api/packages/TDLM/generic/tdlm-client/latest";
+            "https://maven.dandanton.com/repository/tdlm-client";
 
     /// Stable client update root (`server-manifest.json` and `overrides/` live under this URL).
     ///
@@ -165,11 +165,14 @@ public final class Metadata {
         return getClientFileApi() + "/server-manifest.json";
     }
 
+    /// Fallback join address when the installed modpack manifest has no `serverAddress` / routes.
+    public static final String DEFAULT_SERVER_ADDRESS = "mc.potatolab.uk";
+
     /// Server address used when the installed modpack manifest does not provide one.
     ///
-    /// Can be set at build or run time with the `hmcl.server.address` system property; empty by default.
+    /// Override at build or run time with `-Dhmcl.server.address=…`; defaults to [#DEFAULT_SERVER_ADDRESS].
     public static String getDefaultServerAddress() {
-        return System.getProperty("hmcl.server.address", "").trim();
+        return System.getProperty("hmcl.server.address", DEFAULT_SERVER_ADDRESS).trim();
     }
 
     /// The server name shown in the title bar.

HMCL/src/main/java/org/jackhuang/hmcl/game/ModpackHelper.java

@@ -19,7 +19,6 @@ import org.jackhuang.hmcl.modpack.server.ServerModpackRemoteInstallTask;
 import org.jackhuang.hmcl.setting.*;
 import org.jackhuang.hmcl.task.Schedulers;
 import org.jackhuang.hmcl.task.Task;
-import org.jackhuang.hmcl.util.Lang;
 import org.jackhuang.hmcl.util.PortablePath;
 import org.jackhuang.hmcl.util.function.ExceptionalConsumer;
 import org.jackhuang.hmcl.util.function.ExceptionalRunnable;
@@ -44,6 +43,7 @@ import java.util.Set;
 
 import static org.jackhuang.hmcl.util.Lang.mapOf;
 import static org.jackhuang.hmcl.util.Pair.pair;
+import static org.jackhuang.hmcl.util.logging.Logger.LOG;
 
 /// Utilities for reading, installing, and applying modpack-specific game settings.
 @NotNullByDefault
@@ -314,18 +314,13 @@ public final class ModpackHelper {
             setting.minMemoryProperty().setValue(c.getMinMemory());
         }
 
+        // MultiMC packs are untrusted input: never auto-apply PreLaunch/Wrapper/JVM overrides.
         if (c.isOverrideCommands()) {
-            setting.getOverrideProperties().addAll(List.of(
-                    GameSettings.PROPERTY_COMMAND_WRAPPER,
-                    GameSettings.PROPERTY_PRE_LAUNCH_COMMAND
-            ));
-            setting.commandWrapperProperty().setValue(Objects.requireNonNullElse(c.getWrapperCommand(), ""));
-            setting.preLaunchCommandProperty().setValue(Objects.requireNonNullElse(c.getPreLaunchCommand(), ""));
+            LOG.warning("Ignoring MultiMC OverrideCommands (PreLaunch/Wrapper) from modpack for security");
         }
 
         if (c.isOverrideJavaArgs()) {
-            setting.getOverrideProperties().add(GameSettings.PROPERTY_JVM_OPTIONS);
-            setting.jvmOptionsProperty().setValue(Objects.requireNonNullElse(c.getJvmArgs(), ""));
+            LOG.warning("Ignoring MultiMC OverrideJavaArgs from modpack for security");
         }
 
         if (c.isOverrideConsole()) {
@@ -348,18 +343,13 @@ public final class ModpackHelper {
     }
 
     private static void applyCommandAndJvmSettings(MultiMCInstanceConfiguration c, GameSettings.Instance setting) {
+        // Same policy as toGameSettings: do not import executable commands / raw JVM args from packs.
         if (c.isOverrideCommands()) {
-            setting.getOverrideProperties().addAll(List.of(
-                    GameSettings.PROPERTY_COMMAND_WRAPPER,
-                    GameSettings.PROPERTY_PRE_LAUNCH_COMMAND
-            ));
-            setting.commandWrapperProperty().setValue(Lang.nonNull(c.getWrapperCommand(), ""));
-            setting.preLaunchCommandProperty().setValue(Lang.nonNull(c.getPreLaunchCommand(), ""));
+            LOG.warning("Ignoring MultiMC OverrideCommands (PreLaunch/Wrapper) from modpack update for security");
         }
 
         if (c.isOverrideJavaArgs()) {
-            setting.getOverrideProperties().add(GameSettings.PROPERTY_JVM_OPTIONS);
-            setting.jvmOptionsProperty().setValue(Lang.nonNull(c.getJvmArgs(), ""));
+            LOG.warning("Ignoring MultiMC OverrideJavaArgs from modpack update for security");
         }
     }
 

HMCL/src/main/java/org/jackhuang/hmcl/ui/Controllers.java

@@ -398,12 +398,22 @@ public final class Controllers {
                         .whenComplete(Schedulers.javafx(), (result, exception) -> {
                             if (exception != null) {
                                 LOG.warning("Failed to fetch client Server Modpack manifest", exception);
+                                Controllers.dialog(
+                                        manifestUrl + "\n" + exception.getMessage(),
+                                        i18n("message.error"),
+                                        MessageType.ERROR);
+                                Instances.importModpack();
                                 return;
                             }
                             ServerModpackManifest manifest =
                                     JsonUtils.fromMaybeMalformedJson(result, ServerModpackManifest.class);
                             if (manifest == null) {
                                 LOG.warning("Malformed client Server Modpack manifest from " + manifestUrl);
+                                Controllers.dialog(
+                                        i18n("modpack.type.server.malformed"),
+                                        i18n("message.error"),
+                                        MessageType.ERROR);
+                                Instances.importModpack();
                                 return;
                             }
                             Controllers.getDecorator().startWizard(

HMCL/src/main/java/org/jackhuang/hmcl/ui/FXUtils.java

@@ -602,6 +602,10 @@ public final class FXUtils {
             return;
 
         String url = NetworkUtils.encodeLocation(link);
+        if (!isAllowedOpenLink(url)) {
+            LOG.warning("Refusing to open link with disallowed scheme: " + link);
+            return;
+        }
         thread(() -> {
             try {
                 if (OperatingSystem.CURRENT_OS == OperatingSystem.WINDOWS) {
@@ -635,6 +639,23 @@ public final class FXUtils {
         });
     }
 
+    /// Only {@code http}/{@code https}/{@code mailto} may be handed to the OS URL handler.
+    static boolean isAllowedOpenLink(String link) {
+        try {
+            URI uri = new URI(link);
+            String scheme = uri.getScheme();
+            if (scheme == null) {
+                return false;
+            }
+            return switch (scheme.toLowerCase(java.util.Locale.ROOT)) {
+                case "http", "https", "mailto" -> true;
+                default -> false;
+            };
+        } catch (Exception e) {
+            return false;
+        }
+    }
+
     public static <T> void bind(JFXTextField textField, Property<T> property, StringConverter<T> converter) {
         TextFieldBinding<T> binding = new TextFieldBinding<>(textField, property, converter);
         binding.updateTextField();

HMCL/src/test/java/org/jackhuang/hmcl/game/ServerEndpointTest.java

@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: GPL-3.0-or-later WITH AdditionRef-HMCL
 package org.jackhuang.hmcl.game;
 
+import org.jackhuang.hmcl.Metadata;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
@@ -19,13 +20,15 @@ public final class ServerEndpointTest {
     }
 
     @Test
-    void noConfigurationMeansNoRoute(@TempDir Path dir) {
-        assertTrue(ServerEndpoint.routes(dir.resolve("modpack.json")).isEmpty());
-        assertNull(ServerEndpoint.selected(dir.resolve("modpack.json")));
+    void fallsBackToBakedDefaultAddress(@TempDir Path dir) {
+        var routes = ServerEndpoint.routes(dir.resolve("modpack.json"));
+        assertEquals(1, routes.size());
+        assertEquals(Metadata.DEFAULT_SERVER_ADDRESS, routes.get(0).address());
+        assertEquals(routes.get(0), ServerEndpoint.selected(dir.resolve("modpack.json")));
     }
 
     @Test
-    void fallsBackToDefaultAddress(@TempDir Path dir) {
+    void propertyOverridesBakedDefaultAddress(@TempDir Path dir) {
         System.setProperty("hmcl.server.address", " play.example.net:25565 ");
         var routes = ServerEndpoint.routes(dir.resolve("modpack.json"));
         assertEquals(1, routes.size());

HMCLBoot/src/main/java/org/jackhuang/hmcl/DesktopUtils.java

@@ -42,6 +42,11 @@ public final class DesktopUtils {
     }
 
     public static void openLink(String link) {
+        if (!isAllowedOpenLink(link)) {
+            System.err.println("Refusing to open link with disallowed scheme: " + link);
+            return;
+        }
+
         String osName = System.getProperty("os.name").toLowerCase(Locale.ROOT);
 
         Throwable e1 = null;
@@ -79,6 +84,21 @@ public final class DesktopUtils {
         }
     }
 
+    /// Only {@code http}/{@code https}/{@code mailto} may be handed to the OS URL handler.
+    static boolean isAllowedOpenLink(String link) {
+        try {
+            URI uri = new URI(link);
+            String scheme = uri.getScheme();
+            if (scheme == null) {
+                return false;
+            }
+            String lower = scheme.toLowerCase(Locale.ROOT);
+            return "http".equals(lower) || "https".equals(lower) || "mailto".equals(lower);
+        } catch (Exception e) {
+            return false;
+        }
+    }
+
     private DesktopUtils() {
     }
 }

HMCLCore/src/main/java/org/jackhuang/hmcl/auth/authlibinjector/AuthlibInjectorServer.java

@@ -45,10 +45,18 @@ public class AuthlibInjectorServer implements Observable {
             String ali = conn.getHeaderField("x-authlib-injector-api-location");
             if (ali != null) {
                 WebURL absoluteAli = WebURL.parse(ali, WebURL.of(conn.getURL()));
+                // Only follow same-host HTTPS redirects; open redirects to other hosts are rejected.
                 if (!urlEqualsIgnoreSlash(webURL.toString(), absoluteAli.toString())) {
-                    conn.disconnect();
-                    url = absoluteAli.toString();
-                    conn = NetworkUtils.resolveConnection(NetworkUtils.createHttpConnection(absoluteAli));
+                    if (!"https".equalsIgnoreCase(absoluteAli.getScheme())
+                            || absoluteAli.getHost() == null
+                            || webURL.getHost() == null
+                            || !absoluteAli.getHost().equalsIgnoreCase(webURL.getHost())) {
+                        LOG.warning("Ignoring x-authlib-injector-api-location redirect outside original HTTPS host: " + absoluteAli);
+                    } else {
+                        conn.disconnect();
+                        url = absoluteAli.toString();
+                        conn = NetworkUtils.resolveConnection(NetworkUtils.createHttpConnection(absoluteAli));
+                    }
                 }
             }
 

HMCLCore/src/main/java/org/jackhuang/hmcl/modpack/multimc/MultiMCInstancePatch.java

@@ -7,6 +7,7 @@ import com.google.gson.annotations.SerializedName;
 
 import org.jackhuang.hmcl.game.*;
 import org.jackhuang.hmcl.util.Immutable;
+import org.jackhuang.hmcl.util.JvmArgumentFilter;
 import org.jackhuang.hmcl.util.Lang;
 import org.jackhuang.hmcl.util.StringUtils;
 import org.jackhuang.hmcl.util.gson.JsonUtils;
@@ -282,7 +283,7 @@ public final class MultiMCInstancePatch {
             if (minecraftArguments == null & patch.getMinecraftArguments() != null) {
                 minecraftArguments = StringUtils.tokenize(patch.getMinecraftArguments());
             }
-            for (String jvmArg : patch.getJvmArgs()) {
+            for (String jvmArg : JvmArgumentFilter.filter(patch.getJvmArgs())) {
                 jvmArguments.add(new StringArgument(jvmArg));
             }
             mainClass = Lang.requireNonNullElse(mainClass, patch.getMainClass());

HMCLCore/src/main/java/org/jackhuang/hmcl/modpack/server/Lwjgl3ifySupport.java

@@ -5,6 +5,7 @@ package org.jackhuang.hmcl.modpack.server;
 import org.jackhuang.hmcl.game.LaunchOptions;
 import org.jackhuang.hmcl.modpack.multimc.MultiMCInstancePatch;
 import org.jackhuang.hmcl.modpack.multimc.MultiMCManifest;
+import org.jackhuang.hmcl.util.JvmArgumentFilter;
 import org.jackhuang.hmcl.util.gson.JsonUtils;
 import org.jetbrains.annotations.NotNullByDefault;
 
@@ -55,7 +56,7 @@ public final class Lwjgl3ifySupport {
                 try {
                     MultiMCInstancePatch patch = MultiMCInstancePatch.read(
                             patchFile.getFileName().toString(), Files.readString(patchFile));
-                    args.addAll(patch.getJvmArgs());
+                    args.addAll(JvmArgumentFilter.filter(patch.getJvmArgs()));
                 } catch (IOException | RuntimeException e) {
                     LOG.warning("Failed to read lwjgl3ify patch " + patchFile, e);
                 }

HMCLCore/src/main/java/org/jackhuang/hmcl/util/JvmArgumentFilter.java

@@ -0,0 +1,57 @@
+// SPDX-FileCopyrightText: Copyright (C) 2026 The HMCL Authors
+// SPDX-License-Identifier: GPL-3.0-or-later WITH AdditionRef-HMCL
+package org.jackhuang.hmcl.util;
+
+import org.jetbrains.annotations.Nullable;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Locale;
+
+import static org.jackhuang.hmcl.util.logging.Logger.LOG;
+
+/**
+ * Filters JVM arguments coming from untrusted modpack / MultiMC patch input.
+ *
+ * <p>Denies agent injection and {@code -XX:On*Error} command hooks while allowing ordinary
+ * memory / GC / system-property args used by companions such as lwjgl3ify.
+ */
+public final class JvmArgumentFilter {
+    private JvmArgumentFilter() {
+    }
+
+    /// Returns whether a single JVM argument is safe to accept from modpack / patch metadata.
+    public static boolean isAllowed(@Nullable String arg) {
+        if (arg == null) {
+            return false;
+        }
+        String trimmed = arg.trim();
+        if (trimmed.isEmpty()) {
+            return false;
+        }
+        String lower = trimmed.toLowerCase(Locale.ROOT);
+        if (lower.startsWith("-javaagent")
+                || lower.startsWith("-agentpath")
+                || lower.startsWith("-agentlib")
+                || lower.startsWith("-xbootclasspath")
+                || lower.startsWith("-xx:onoutofmemoryerror")
+                || lower.startsWith("-xx:onerror")
+                || lower.startsWith("-xx:exitonoutofmemoryerror")) {
+            return false;
+        }
+        return true;
+    }
+
+    /// Copies {@code args}, dropping disallowed entries and logging each skip.
+    public static List<String> filter(Iterable<String> args) {
+        List<String> out = new ArrayList<>();
+        for (String arg : args) {
+            if (isAllowed(arg)) {
+                out.add(arg);
+            } else {
+                LOG.warning("Ignoring disallowed JVM argument from modpack/patch: " + arg);
+            }
+        }
+        return out;
+    }
+}

HMCLCore/src/main/java/org/jackhuang/hmcl/util/io/FileUtils.java

@@ -306,6 +306,7 @@ public final class FileUtils {
     }
 
     public static void copyDirectory(Path src, Path dest, Predicate<String> filePredicate) throws IOException {
+        Path destRoot = dest.toAbsolutePath().normalize();
         Files.walkFileTree(src, new SimpleFileVisitor<>() {
             @Override
             public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
@@ -313,7 +314,11 @@ public final class FileUtils {
                     return FileVisitResult.SKIP_SUBTREE;
                 }
 
-                Path destFile = dest.resolve(src.relativize(file).toString());
+                Path destFile = destRoot.resolve(src.relativize(file).toString()).toAbsolutePath().normalize();
+                if (!destFile.startsWith(destRoot)) {
+                    throw new IOException("Refusing to copy outside destination directory: " + file);
+                }
+                Files.createDirectories(destFile.getParent());
                 Files.copy(file, destFile, StandardCopyOption.REPLACE_EXISTING);
                 return FileVisitResult.CONTINUE;
             }
@@ -324,7 +329,10 @@ public final class FileUtils {
                     return FileVisitResult.SKIP_SUBTREE;
                 }
 
-                Path destDir = dest.resolve(src.relativize(dir).toString());
+                Path destDir = destRoot.resolve(src.relativize(dir).toString()).toAbsolutePath().normalize();
+                if (!destDir.startsWith(destRoot)) {
+                    throw new IOException("Refusing to create directory outside destination: " + dir);
+                }
                 Files.createDirectories(destDir);
                 return FileVisitResult.CONTINUE;
             }

HMCLCore/src/main/java/org/jackhuang/hmcl/util/io/HttpRequest.java

@@ -10,6 +10,7 @@ import org.jackhuang.hmcl.util.function.ExceptionalSupplier;
 import org.jackhuang.hmcl.util.gson.JsonUtils;
 
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.OutputStream;
 import java.net.HttpURLConnection;
 import java.net.MalformedURLException;
@@ -134,9 +135,10 @@ public abstract class HttpRequest {
                 con = resolveConnection(con);
                 checkResponseCode(con);
 
-                return IOUtils.readFullyAsString("gzip".equals(con.getContentEncoding())
+                InputStream body = "gzip".equals(con.getContentEncoding())
                         ? IOUtils.wrapFromGZip(con.getInputStream())
-                        : con.getInputStream());
+                        : con.getInputStream();
+                return IOUtils.readFullyAsString(body, UTF_8, IOUtils.DEFAULT_MAX_HTTP_BODY_BYTES);
             }, retryTimes);
         }
     }

HMCLCore/src/main/java/org/jackhuang/hmcl/util/io/IOUtils.java

@@ -5,7 +5,13 @@ package org.jackhuang.hmcl.util.io;
 import kala.encdet.EncodingDetector;
 import org.jetbrains.annotations.Nullable;
 
-import java.io.*;
+import java.io.BufferedReader;
+import java.io.ByteArrayOutputStream;
+import java.io.EOFException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.OutputStream;
 import java.nio.ByteBuffer;
 import java.nio.channels.Channels;
 import java.nio.channels.FileChannel;
@@ -29,6 +35,9 @@ public final class IOUtils {
 
     public static final int DEFAULT_BUFFER_SIZE = 32 * 1024;
 
+    /// Soft cap for HTTP / metadata bodies read into memory (authlib, API JSON, etc.).
+    public static final long DEFAULT_MAX_HTTP_BODY_BYTES = 16L * 1024L * 1024L;
+
     public static BufferedReader newBufferedReaderMaybeNativeEncoding(Path file) throws IOException {
         if (NATIVE_CHARSET == UTF_8)
             return Files.newBufferedReader(file);
@@ -68,8 +77,29 @@ public final class IOUtils {
     }
 
     public static byte[] readFully(InputStream stream) throws IOException {
+        return readFully(stream, -1L);
+    }
+
+    /// Reads the stream fully, optionally refusing bodies larger than {@code maxBytes}.
+    ///
+    /// @param maxBytes maximum accepted size, or {@code <= 0} for no limit
+    public static byte[] readFully(InputStream stream, long maxBytes) throws IOException {
         try (stream) {
-            return stream.readAllBytes();
+            if (maxBytes <= 0) {
+                return stream.readAllBytes();
+            }
+            ByteArrayOutputStream out = new ByteArrayOutputStream(Math.min(DEFAULT_BUFFER_SIZE, (int) Math.min(maxBytes, Integer.MAX_VALUE)));
+            byte[] buf = new byte[DEFAULT_BUFFER_SIZE];
+            long total = 0;
+            int n;
+            while ((n = stream.read(buf)) >= 0) {
+                total += n;
+                if (total > maxBytes) {
+                    throw new IOException("Response body exceeds limit of " + maxBytes + " bytes");
+                }
+                out.write(buf, 0, n);
+            }
+            return out.toByteArray();
         }
     }
 
@@ -81,6 +111,10 @@ public final class IOUtils {
         return new String(readFully(stream), charset);
     }
 
+    public static String readFullyAsString(InputStream stream, Charset charset, long maxBytes) throws IOException {
+        return new String(readFully(stream, maxBytes), charset);
+    }
+
     public static void skipNBytes(InputStream input, long n) throws IOException {
         while (n > 0) {
             long ns = input.skip(n);

HMCLCore/src/main/java/org/jackhuang/hmcl/util/io/NetworkUtils.java

@@ -437,13 +437,13 @@ public final class NetworkUtils {
             Charset charset = getCharsetFromContentType(con.getHeaderField("Content-Type"));
 
             try (InputStream stdout = con.getInputStream()) {
-                return IOUtils.readFullyAsString(contentEncoding.wrap(stdout), charset);
+                return IOUtils.readFullyAsString(contentEncoding.wrap(stdout), charset, IOUtils.DEFAULT_MAX_HTTP_BODY_BYTES);
             } catch (IOException e) {
                 if (con instanceof HttpURLConnection) {
                     try (InputStream stderr = ((HttpURLConnection) con).getErrorStream()) {
                         if (stderr == null)
                             throw e;
-                        return IOUtils.readFullyAsString(contentEncoding.wrap(stderr), charset);
+                        return IOUtils.readFullyAsString(contentEncoding.wrap(stderr), charset, IOUtils.DEFAULT_MAX_HTTP_BODY_BYTES);
                     }
                 } else {
                     throw e;

HMCLCore/src/test/java/org/jackhuang/hmcl/util/JvmArgumentFilterTest.java

@@ -0,0 +1,34 @@
+// SPDX-FileCopyrightText: Copyright (C) 2026 The HMCL Authors
+// SPDX-License-Identifier: GPL-3.0-or-later WITH AdditionRef-HMCL
+package org.jackhuang.hmcl.util;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class JvmArgumentFilterTest {
+    @Test
+    public void allowsOrdinaryArgs() {
+        assertTrue(JvmArgumentFilter.isAllowed("-Xmx2G"));
+        assertTrue(JvmArgumentFilter.isAllowed("-Djava.library.path=/tmp"));
+        assertTrue(JvmArgumentFilter.isAllowed("--add-opens=java.base/java.lang=ALL-UNNAMED"));
+    }
+
+    @Test
+    public void rejectsAgentsAndOnErrorHooks() {
+        assertFalse(JvmArgumentFilter.isAllowed("-javaagent:/tmp/evil.jar"));
+        assertFalse(JvmArgumentFilter.isAllowed("-agentpath:/tmp/evil.so"));
+        assertFalse(JvmArgumentFilter.isAllowed("-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=*:5005"));
+        assertFalse(JvmArgumentFilter.isAllowed("-Xbootclasspath/a:/tmp/evil.jar"));
+        assertFalse(JvmArgumentFilter.isAllowed("-XX:OnOutOfMemoryError=curl evil.example"));
+        assertFalse(JvmArgumentFilter.isAllowed("-XX:OnError=id"));
+    }
+
+    @Test
+    public void filterDropsDisallowed() {
+        assertEquals(List.of("-Xmx1G"),
+                JvmArgumentFilter.filter(List.of("-Xmx1G", "-javaagent:x.jar")));
+    }
+}

HMCLCore/src/test/java/org/jackhuang/hmcl/util/io/CopyDirectoryTraversalTest.java

@@ -0,0 +1,36 @@
+// SPDX-FileCopyrightText: Copyright (C) 2026 The HMCL Authors
+// SPDX-License-Identifier: GPL-3.0-or-later WITH AdditionRef-HMCL
+package org.jackhuang.hmcl.util.io;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class CopyDirectoryTraversalTest {
+    @TempDir
+    Path temp;
+
+    @Test
+    public void copiesWithinDestination() throws IOException {
+        Path src = temp.resolve("src");
+        Path dest = temp.resolve("dest");
+        Files.createDirectories(src.resolve("a"));
+        Files.writeString(src.resolve("a/b.txt"), "hi");
+        FileUtils.copyDirectory(src, dest);
+        assertEquals("hi", Files.readString(dest.resolve("a/b.txt")));
+    }
+
+    @Test
+    public void destinationRootGuardMatchesUnzipperStyle() {
+        Path destRoot = temp.resolve("dest").toAbsolutePath().normalize();
+        Path escape = destRoot.resolve("sub/../../outside.txt").toAbsolutePath().normalize();
+        assertFalse(escape.startsWith(destRoot), "normalize + startsWith must reject escapes");
+        Path inside = destRoot.resolve("sub/file.txt").toAbsolutePath().normalize();
+        assertTrue(inside.startsWith(destRoot));
+    }
+}

HMCLCore/src/test/java/org/jackhuang/hmcl/util/io/IOUtilsReadLimitTest.java

@@ -0,0 +1,26 @@
+// SPDX-FileCopyrightText: Copyright (C) 2026 The HMCL Authors
+// SPDX-License-Identifier: GPL-3.0-or-later WITH AdditionRef-HMCL
+package org.jackhuang.hmcl.util.io;
+
+import org.junit.jupiter.api.Test;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+public class IOUtilsReadLimitTest {
+    @Test
+    public void rejectsOversizedBody() {
+        byte[] data = new byte[100];
+        assertThrows(IOException.class, () -> IOUtils.readFully(new ByteArrayInputStream(data), 50));
+    }
+
+    @Test
+    public void acceptsWithinLimit() throws IOException {
+        byte[] data = "hello".getBytes(StandardCharsets.UTF_8);
+        assertArrayEquals(data, IOUtils.readFully(new ByteArrayInputStream(data), 16));
+        assertEquals("hello", IOUtils.readFullyAsString(new ByteArrayInputStream(data), StandardCharsets.UTF_8, 16));
+    }
+}

docs/TDLM_CONSUME.md

@@ -0,0 +1,71 @@
+# TDLMPack consume path for TDLM/HMCL
+
+TDLMPack does **not** pull this launcher via Maven, a version pin, or a pack-build download step.
+The pack build publishes the HMCL Server Modpack client (`server-manifest.json` + `overrides/`)
+under the `tdlm-client/latest` layout. Players install the launcher separately.
+
+## After this repo’s publish workflow
+
+Run **Actions → Publish TDLM launcher → Run workflow** with a new `release_tag`.
+
+### Secrets (sibling pattern)
+
+| Name | Where it lives today | Used by |
+|---|---|---|
+| `MAVEN_USER` / `MAVEN_PASSWORD` | **Org** secrets | Stratum / mod Maven publish — **not** used for launcher binaries |
+| `TDLM_PACK_TOKEN` | **TDLMPack repo** secret only (not org) | TDLMPack `pack.yml` Gitea package + release uploads |
+| `github.token` | Actions runtime | HMCL publish fallback when `TDLM_PACK_TOKEN` is unset |
+
+HMCL `publish-tdlm.yml` uses the **same name** as TDLMPack: `secrets.TDLM_PACK_TOKEN`, then falls back to `github.token`.
+Org Maven secrets cannot publish Gitea generic packages / releases.
+
+**Recommended:** promote `TDLM_PACK_TOKEN` to an **org** secret (like `MAVEN_*`) so HMCL inherits it with no new repo secret. Until then, either copy it onto `TDLM/HMCL` or rely on `github.token` (same-repo release usually works; org `tdlm-hmcl` package write may still need the pack token).
+
+### 1. Stable generic URLs (preferred for README / curl / CI)
+
+Overwrite-in-place, same host style as the client fileApi:
+
+```text
+https://git.nest.potatolab.uk:8443/api/packages/TDLM/generic/tdlm-hmcl/latest/HMCL.exe
+https://git.nest.potatolab.uk:8443/api/packages/TDLM/generic/tdlm-hmcl/latest/HMCL.jar
+```
+
+Checksums (when published): `HMCL.exe.sha256`, `HMCL.jar.sha256` next to those names.
+
+### 2. Gitea Release (versioned page)
+
+```text
+https://git.potatolab.uk/TDLM/HMCL/releases/latest
+```
+
+Assets on each tag: `HMCL.exe`, `HMCL.jar`, plus `.sha256` files.
+(Use the nest API host for scripted uploads; public download links on `git.potatolab.uk` are fine for browsers.)
+
+### 3. What TDLMPack should change
+
+In `TDLM/TDLMPack` README §启动, replace the repo-only “安装 TDLM/HMCL” step with one of the URLs above.
+**Do not** add HMCL as a Gradle/Maven dependency of the pack — pack CI stays pack-only.
+
+### 4. Client pack fileApi (CDN)
+
+HMCL default (`Metadata.DEFAULT_CLIENT_FILE_API`):
+
+```text
+https://packages.dandanton.com/tdlm-client/latest
+```
+
+First install / updates fetch `{fileApi}/server-manifest.json` (and `overrides/**` under that root).
+Override at runtime: `-Dhmcl.client.fileApi=…` or jar attribute `hmcl.client.fileApi`.
+
+**TDLMPack must use the same URL** so `server-manifest.json` embeds it:
+
+```text
+TDLM_CLIENT_FILE_API=https://packages.dandanton.com/tdlm-client/latest
+```
+
+Set that as the Gitea Actions **variable** on `TDLM/TDLMPack` (pack.yml already passes `vars.TDLM_CLIENT_FILE_API`).
+
+**Publish caveat:** Pack’s current workflow PUTs the client tree to whatever `TDLM_CLIENT_FILE_API` is (upload root = fileApi). Today that defaults to Gitea generic
+`https://git.nest.potatolab.uk:8443/api/packages/TDLM/generic/tdlm-client/latest`.
+If you only change the HMCL default to the CDN and leave Pack publishing to Gitea, players will 404 unless you **mirror/sync** Gitea → `packages.dandanton.com/tdlm-client/latest`.
+If you set `TDLM_CLIENT_FILE_API` to the CDN URL, Pack CI must be able to PUT to that CDN (or you must split “upload origin” from “public fileApi” in Pack — not implemented today). Do not point HMCL at the CDN without one of those two ops paths.