diff --git a/CHANGELOG.md b/CHANGELOG.md
index 38c29cff9a4..3912be92767 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -58,6 +58,7 @@ Docs: https://docs.openclaw.ai
 - Gateway/restart: preserve one-shot continuation instructions across gateway restarts so agents can resume and reply back to the original chat after reboot. (#63406) Thanks @VACInc.
 - Gateway/restart: write restart sentinel files atomically so interrupted writes cannot leave a truncated sentinel behind. (#70225) Thanks @obviyus.
 - Pairing: remove stale pending requests for a device when that paired device is deleted, so an old repair approval cannot recreate the removed device from leftover state.
+- Security/dotenv: block workspace `.env` overrides for Matrix, Mattermost, IRC, and Synology endpoint settings so cloned workspaces cannot redirect bundled connector traffic through local endpoint config. (#70240) Thanks @drobison00.
 
 ## 2026.4.21
 
diff --git a/src/infra/dotenv.test.ts b/src/infra/dotenv.test.ts
index 9e5617009bb..9940cf56a42 100644
--- a/src/infra/dotenv.test.ts
+++ b/src/infra/dotenv.test.ts
@@ -624,6 +624,9 @@ describe("workspace .env blocklist completeness", () => {
           "OPENCLAW_ALLOW_INSECURE_PRIVATE_WS",
           "OPENCLAW_BROWSER_EXECUTABLE_PATH",
           "EXAMPLE_API_HOST",
+          "IRC_HOST",
+          "MATTERMOST_URL",
+          "MATRIX_HOMESERVER",
           "MINIMAX_API_HOST",
           "BROWSER_EXECUTABLE_PATH",
           "PLAYWRIGHT_CHROMIUM_EXECUTABLE_PATH",
@@ -643,6 +646,8 @@ describe("workspace .env blocklist completeness", () => {
           "OPENCLAW_NODE_EXEC_HOST",
           "OPENCLAW_NODE_EXEC_FALLBACK",
           "OPENCLAW_ALLOW_PROJECT_LOCAL_BIN",
+          "SYNOLOGY_CHAT_INCOMING_URL",
+          "SYNOLOGY_NAS_HOST",
         ];
 
         await writeEnvFile(
@@ -684,6 +689,62 @@ describe("workspace .env blocklist completeness", () => {
     });
   });
 
+  it("blocks bundled connector endpoint vars from workspace .env", async () => {
+    await withIsolatedEnvAndCwd(async () => {
+      await withDotEnvFixture(async ({ cwdDir }) => {
+        await writeEnvFile(
+          path.join(cwdDir, ".env"),
+          [
+            "MATRIX_HOMESERVER=https://evil-matrix.example.com",
+            "MATTERMOST_URL=https://evil-mattermost.example.com",
+            "IRC_HOST=evil-irc.example.com",
+            "SYNOLOGY_CHAT_INCOMING_URL=https://evil-synology.example.com/incoming",
+            "SYNOLOGY_NAS_HOST=evil-synology.example.com",
+            "SAFE_PROVIDER_URL=https://allowed.example.com",
+          ].join("\n"),
+        );
+
+        delete process.env.MATRIX_HOMESERVER;
+        delete process.env.MATTERMOST_URL;
+        delete process.env.IRC_HOST;
+        delete process.env.SYNOLOGY_CHAT_INCOMING_URL;
+        delete process.env.SYNOLOGY_NAS_HOST;
+        delete process.env.SAFE_PROVIDER_URL;
+
+        loadWorkspaceDotEnvFile(path.join(cwdDir, ".env"), { quiet: true });
+
+        expect(process.env.MATRIX_HOMESERVER).toBeUndefined();
+        expect(process.env.MATTERMOST_URL).toBeUndefined();
+        expect(process.env.IRC_HOST).toBeUndefined();
+        expect(process.env.SYNOLOGY_CHAT_INCOMING_URL).toBeUndefined();
+        expect(process.env.SYNOLOGY_NAS_HOST).toBeUndefined();
+        expect(process.env.SAFE_PROVIDER_URL).toBe("https://allowed.example.com");
+      });
+    });
+  });
+
+  it("blocks Matrix per-account scoped homeserver vars from workspace .env", async () => {
+    await withIsolatedEnvAndCwd(async () => {
+      await withDotEnvFixture(async ({ cwdDir }) => {
+        await writeEnvFile(
+          path.join(cwdDir, ".env"),
+          [
+            "MATRIX_DEFAULT_HOMESERVER=https://evil-default.example.com",
+            "MATRIX_OPS_HOMESERVER=https://evil-ops.example.com",
+          ].join("\n"),
+        );
+
+        delete process.env.MATRIX_DEFAULT_HOMESERVER;
+        delete process.env.MATRIX_OPS_HOMESERVER;
+
+        loadWorkspaceDotEnvFile(path.join(cwdDir, ".env"), { quiet: true });
+
+        expect(process.env.MATRIX_DEFAULT_HOMESERVER).toBeUndefined();
+        expect(process.env.MATRIX_OPS_HOMESERVER).toBeUndefined();
+      });
+    });
+  });
+
   it("blocks generic endpoint-routing suffixes from workspace .env", async () => {
     await withIsolatedEnvAndCwd(async () => {
       await withDotEnvFixture(async ({ cwdDir }) => {
diff --git a/src/infra/dotenv.ts b/src/infra/dotenv.ts
index 391c30778af..631ae7cf113 100644
--- a/src/infra/dotenv.ts
+++ b/src/infra/dotenv.ts
@@ -21,6 +21,9 @@ const BLOCKED_WORKSPACE_DOTENV_KEYS = new Set([
   "CLAWHUB_URL",
   "HTTP_PROXY",
   "HTTPS_PROXY",
+  "IRC_HOST",
+  "MATTERMOST_URL",
+  "MATRIX_HOMESERVER",
   "MINIMAX_API_HOST",
   "NODE_TLS_REJECT_UNAUTHORIZED",
   "NO_PROXY",
@@ -66,11 +69,15 @@ const BLOCKED_WORKSPACE_DOTENV_KEYS = new Set([
   "OPENCLAW_TEST_TAILSCALE_BINARY",
   "PI_CODING_AGENT_DIR",
   "PLAYWRIGHT_CHROMIUM_EXECUTABLE_PATH",
+  "SYNOLOGY_CHAT_INCOMING_URL",
+  "SYNOLOGY_NAS_HOST",
   "UV_PYTHON",
 ]);
 
 // Block endpoint redirection for any service without overfitting per-provider names.
-const BLOCKED_WORKSPACE_DOTENV_SUFFIXES = ["_API_HOST", "_BASE_URL"];
+// `_HOMESERVER` covers Matrix's per-account scoped keys (MATRIX_<ACCOUNT>_HOMESERVER)
+// in addition to the bare MATRIX_HOMESERVER listed above.
+const BLOCKED_WORKSPACE_DOTENV_SUFFIXES = ["_API_HOST", "_BASE_URL", "_HOMESERVER"];
 const BLOCKED_WORKSPACE_DOTENV_PREFIXES = [
   "ANTHROPIC_API_KEY_",
   "CLAWHUB_",