fix(core): resolve swallowed directory mismatch in IDE connections (#28729)

Co-authored-by: David Pierce <davidapierce@google.com>

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "@google/gemini-cli",
-  "version": "0.55.1",
+  "version": "0.56.0-nightly.20260806.g761f604c1",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@google/gemini-cli",
-      "version": "0.55.1",
+      "version": "0.56.0-nightly.20260806.g761f604c1",
       "workspaces": [
         "packages/*"
       ],
@@ -17782,7 +17782,7 @@
     },
     "packages/a2a-server": {
       "name": "@google/gemini-cli-a2a-server",
-      "version": "0.55.1",
+      "version": "0.56.0-nightly.20260806.g761f604c1",
       "dependencies": {
         "@a2a-js/sdk": "0.3.11",
         "@google-cloud/storage": "7.19.0",
@@ -18242,7 +18242,7 @@
     },
     "packages/cli": {
       "name": "@google/gemini-cli",
-      "version": "0.55.1",
+      "version": "0.56.0-nightly.20260806.g761f604c1",
       "license": "Apache-2.0",
       "dependencies": {
         "@agentclientprotocol/sdk": "0.16.1",
@@ -18458,7 +18458,7 @@
     },
     "packages/core": {
       "name": "@google/gemini-cli-core",
-      "version": "0.55.1",
+      "version": "0.56.0-nightly.20260806.g761f604c1",
       "license": "Apache-2.0",
       "dependencies": {
         "@a2a-js/sdk": "0.3.11",
@@ -19131,7 +19131,7 @@
     },
     "packages/devtools": {
       "name": "@google/gemini-cli-devtools",
-      "version": "0.55.1",
+      "version": "0.56.0-nightly.20260806.g761f604c1",
       "license": "Apache-2.0",
       "dependencies": {
         "ws": "8.16.0"
@@ -19167,7 +19167,7 @@
     },
     "packages/sdk": {
       "name": "@google/gemini-cli-sdk",
-      "version": "0.55.1",
+      "version": "0.56.0-nightly.20260806.g761f604c1",
       "license": "Apache-2.0",
       "dependencies": {
         "@google/gemini-cli-core": "file:../core",
@@ -19506,7 +19506,7 @@
     },
     "packages/test-utils": {
       "name": "@google/gemini-cli-test-utils",
-      "version": "0.55.1",
+      "version": "0.56.0-nightly.20260806.g761f604c1",
       "license": "Apache-2.0",
       "dependencies": {
         "@google/gemini-cli-core": "file:../core",
@@ -19524,7 +19524,7 @@
     },
     "packages/vscode-ide-companion": {
       "name": "gemini-cli-vscode-ide-companion",
-      "version": "0.55.1",
+      "version": "0.56.0-nightly.20260806.g761f604c1",
       "license": "LICENSE",
       "dependencies": {
         "@modelcontextprotocol/sdk": "1.23.0",

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@google/gemini-cli",
-  "version": "0.55.1",
+  "version": "0.56.0-nightly.20260806.g761f604c1",
   "engines": {
     "node": ">=20.0.0"
   },
@@ -14,7 +14,7 @@
     "url": "git+https://github.com/google-gemini/gemini-cli.git"
   },
   "config": {
-    "sandboxImageUri": "us-docker.pkg.dev/gemini-code-dev/gemini-cli/sandbox:0.55.1"
+    "sandboxImageUri": "us-docker.pkg.dev/gemini-code-dev/gemini-cli/sandbox:0.56.0-nightly.20260806.g761f604c1"
   },
   "scripts": {
     "start": "cross-env NODE_ENV=development node scripts/start.js",

packages/a2a-server/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@google/gemini-cli-a2a-server",
-  "version": "0.55.1",
+  "version": "0.56.0-nightly.20260806.g761f604c1",
   "description": "Gemini CLI A2A Server",
   "repository": {
     "type": "git",

packages/cli/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@google/gemini-cli",
-  "version": "0.55.1",
+  "version": "0.56.0-nightly.20260806.g761f604c1",
   "description": "Gemini CLI",
   "license": "Apache-2.0",
   "repository": {
@@ -27,7 +27,7 @@
     "dist"
   ],
   "config": {
-    "sandboxImageUri": "us-docker.pkg.dev/gemini-code-dev/gemini-cli/sandbox:0.55.1"
+    "sandboxImageUri": "us-docker.pkg.dev/gemini-code-dev/gemini-cli/sandbox:0.56.0-nightly.20260806.g761f604c1"
   },
   "dependencies": {
     "@agentclientprotocol/sdk": "0.16.1",

packages/core/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@google/gemini-cli-core",
-  "version": "0.55.1",
+  "version": "0.56.0-nightly.20260806.g761f604c1",
   "description": "Gemini CLI Core",
   "license": "Apache-2.0",
   "repository": {

packages/core/src/ide/ide-connection-utils.test.ts

@@ -31,6 +31,21 @@ vi.mock('node:fs', async (importOriginal) => {
       ...actual.promises,
       readFile: vi.fn(),
       readdir: vi.fn(),
+      realpath: vi.fn((p) => Promise.resolve(p)),
+      stat: vi.fn(() =>
+        Promise.resolve({ uid: process.getuid ? process.getuid() : 1000 }),
+      ),
+      open: vi.fn((filePath: string) =>
+        Promise.resolve({
+          stat: () => fs.promises.stat(filePath),
+          readFile: (options?: string | { encoding?: string }) =>
+            fs.promises.readFile(
+              filePath,
+              options as unknown as BufferEncoding | undefined,
+            ),
+          close: () => Promise.resolve(),
+        } as unknown as fs.promises.FileHandle),
+      ),
     },
     realpathSync: (p: string) => p,
     existsSync: vi.fn(() => false),
@@ -430,6 +445,141 @@ describe('ide-connection-utils', () => {
 
       expect(result).toEqual(config2);
     });
+
+    it('should NOT filter out config if all found config files are mismatched/invalid workspaces, returning the best sorted match so that the correct Directory Mismatch error is raised downstream', async () => {
+      const invalidConfig1 = {
+        port: '1111',
+        workspacePath: '/invalid/workspace1',
+      };
+      const invalidConfig2 = {
+        port: '2222',
+        workspacePath: '/invalid/workspace2',
+      };
+      vi.mocked(fs.promises.readFile).mockRejectedValueOnce(
+        new Error('not found'),
+      );
+      (
+        vi.mocked(fs.promises.readdir) as Mock<
+          (path: fs.PathLike) => Promise<string[]>
+        >
+      ).mockResolvedValue([
+        'gemini-ide-server-12345-111.json',
+        'gemini-ide-server-12345-222.json',
+      ]);
+      vi.mocked(fs.promises.readFile)
+        .mockResolvedValueOnce(JSON.stringify(invalidConfig1))
+        .mockResolvedValueOnce(JSON.stringify(invalidConfig2));
+
+      const result = await getConnectionConfigFromFile(12345);
+
+      expect(result).toEqual(invalidConfig1);
+    });
+
+    it('should prioritize the config matching the port from the environment variable when all found config files are mismatched/invalid workspaces', async () => {
+      vi.stubEnv('GEMINI_CLI_IDE_SERVER_PORT', '2222');
+      const invalidConfig1 = {
+        port: '1111',
+        workspacePath: '/invalid/workspace1',
+      };
+      const invalidConfig2 = {
+        port: '2222',
+        workspacePath: '/invalid/workspace2',
+      };
+      vi.mocked(fs.promises.readFile).mockRejectedValueOnce(
+        new Error('not found'),
+      );
+      (
+        vi.mocked(fs.promises.readdir) as Mock<
+          (path: fs.PathLike) => Promise<string[]>
+        >
+      ).mockResolvedValue([
+        'gemini-ide-server-12345-111.json',
+        'gemini-ide-server-12345-222.json',
+      ]);
+      vi.mocked(fs.promises.readFile)
+        .mockResolvedValueOnce(JSON.stringify(invalidConfig1))
+        .mockResolvedValueOnce(JSON.stringify(invalidConfig2));
+
+      const result = await getConnectionConfigFromFile(12345);
+
+      expect(result).toEqual(invalidConfig2);
+    });
+
+    it.runIf(process.getuid !== undefined)(
+      'should reject and ignore config files owned by a different user UID to prevent hijacking/information disclosure',
+      async () => {
+        const config1 = {
+          port: '1111',
+          workspacePath: '/test/workspace',
+        };
+        vi.mocked(fs.promises.readFile).mockRejectedValueOnce(
+          new Error('not found'),
+        );
+        (
+          vi.mocked(fs.promises.readdir) as Mock<
+            (path: fs.PathLike) => Promise<string[]>
+          >
+        ).mockResolvedValue(['gemini-ide-server-12345-111.json']);
+        vi.mocked(fs.promises.readFile).mockResolvedValueOnce(
+          JSON.stringify(config1),
+        );
+
+        const otherUid = (process.getuid ? process.getuid() : 1000) + 1;
+        vi.mocked(fs.promises.stat).mockResolvedValueOnce({
+          uid: otherUid,
+        } as unknown as fs.Stats);
+
+        const result = await getConnectionConfigFromFile(12345);
+
+        expect(result).toBeUndefined();
+      },
+    );
+
+    it('should accept and parse config files owned by the current user UID', async () => {
+      const config1 = {
+        port: '1111',
+        workspacePath: '/test/workspace',
+      };
+      vi.mocked(fs.promises.readFile).mockRejectedValueOnce(
+        new Error('not found'),
+      );
+      (
+        vi.mocked(fs.promises.readdir) as Mock<
+          (path: fs.PathLike) => Promise<string[]>
+        >
+      ).mockResolvedValue(['gemini-ide-server-12345-111.json']);
+      vi.mocked(fs.promises.readFile).mockResolvedValueOnce(
+        JSON.stringify(config1),
+      );
+
+      const currentUid = process.getuid ? process.getuid() : 1000;
+      vi.mocked(fs.promises.stat).mockResolvedValueOnce({
+        uid: currentUid,
+      } as unknown as fs.Stats);
+
+      const result = await getConnectionConfigFromFile(12345);
+
+      expect(result).toEqual(config1);
+    });
+
+    it('should reject and ignore config files if fs.promises.open throws an error', async () => {
+      vi.mocked(fs.promises.readFile).mockRejectedValueOnce(
+        new Error('not found'),
+      );
+      (
+        vi.mocked(fs.promises.readdir) as Mock<
+          (path: fs.PathLike) => Promise<string[]>
+        >
+      ).mockResolvedValue(['gemini-ide-server-12345-111.json']);
+
+      vi.mocked(fs.promises.open).mockRejectedValueOnce(
+        new Error('symlink loop / permission denied'),
+      );
+
+      const result = await getConnectionConfigFromFile(12345);
+
+      expect(result).toBeUndefined();
+    });
   });
 
   describe('validateWorkspacePath', () => {

packages/core/src/ide/ide-connection-utils.ts

@@ -109,6 +109,26 @@ export function getStdioConfigFromEnv(): StdioConfig | undefined {
 
 const IDE_SERVER_FILE_REGEX = /^gemini-ide-server-(\d+)-\d+\.json$/;
 
+async function verifyAndReadFile(
+  filePath: string,
+): Promise<string | undefined> {
+  let handle: fs.promises.FileHandle | undefined;
+  try {
+    handle = await fs.promises.open(filePath, 'r');
+    const stat = await handle.stat();
+    if (process.getuid && stat.uid !== process.getuid()) {
+      return undefined;
+    }
+    return await handle.readFile('utf8');
+  } catch {
+    return undefined;
+  } finally {
+    if (handle) {
+      await handle.close();
+    }
+  }
+}
+
 export async function getConnectionConfigFromFile(
   pid: number,
 ): Promise<
@@ -122,7 +142,10 @@ export async function getConnectionConfigFromFile(
       'ide',
       `gemini-ide-server-${pid}.json`,
     );
-    const portFileContents = await fs.promises.readFile(portFile, 'utf8');
+    const portFileContents = await verifyAndReadFile(portFile);
+    if (!portFileContents) {
+      throw new Error('Verification failed or file not found');
+    }
     const parsed: unknown = JSON.parse(portFileContents);
     type ConfigType = ConnectionConfig & {
       workspacePath?: string;
@@ -164,23 +187,21 @@ export async function getConnectionConfigFromFile(
 
   sortConnectionFiles(matchingFiles, pid);
 
-  let fileContents: string[];
-  try {
-    fileContents = await Promise.all(
-      matchingFiles.map((file) =>
-        fs.promises.readFile(path.join(portFileDir, file), 'utf8'),
-      ),
-    );
-  } catch (e) {
-    logger.debug('Failed to read IDE connection config file(s):', e);
-    return undefined;
-  }
+  const fileContents = await Promise.all(
+    matchingFiles.map((file) =>
+      verifyAndReadFile(path.join(portFileDir, file)),
+    ),
+  );
+
   const parsedContents = fileContents.map(
     (
       content,
     ):
       | (ConnectionConfig & { workspacePath?: string; ideInfo?: IdeInfo })
       | undefined => {
+      if (!content) {
+        return undefined;
+      }
       try {
         const parsed: unknown = JSON.parse(content);
         type ConfigType = ConnectionConfig & {
@@ -219,6 +240,31 @@ export async function getConnectionConfigFromFile(
   );
 
   if (validWorkspaces.length === 0) {
+    // If no workspace matches the current CWD, but we found and parsed
+    // valid connection config file(s), return the best-sorted config.
+    // This lets downstream connection logic raise a helpful, detailed
+    // "Directory mismatch" warning instead of a generic connection error.
+    let fileIndex = -1;
+    const portFromEnv = getPortFromEnv();
+    if (portFromEnv) {
+      fileIndex = parsedContents.findIndex(
+        (content) =>
+          !!content &&
+          content.port !== undefined &&
+          String(content.port) === portFromEnv,
+      );
+    }
+    if (fileIndex === -1) {
+      fileIndex = parsedContents.findIndex((content) => !!content);
+    }
+
+    if (fileIndex !== -1) {
+      const selected = parsedContents[fileIndex]!;
+      logger.debug(
+        `Selected best mismatched IDE connection file: ${matchingFiles[fileIndex]}`,
+      );
+      return selected;
+    }
     return undefined;
   }
 
@@ -234,7 +280,8 @@ export async function getConnectionConfigFromFile(
   const portFromEnv = getPortFromEnv();
   if (portFromEnv) {
     const matchingPortIndex = validWorkspaces.findIndex(
-      (content) => String(content.port) === portFromEnv,
+      (content) =>
+        content.port !== undefined && String(content.port) === portFromEnv,
     );
     if (matchingPortIndex !== -1) {
       const selected = validWorkspaces[matchingPortIndex];

packages/devtools/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@google/gemini-cli-devtools",
-  "version": "0.55.1",
+  "version": "0.56.0-nightly.20260806.g761f604c1",
   "license": "Apache-2.0",
   "type": "module",
   "main": "dist/src/index.js",

packages/sdk/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@google/gemini-cli-sdk",
-  "version": "0.55.1",
+  "version": "0.56.0-nightly.20260806.g761f604c1",
   "description": "Gemini CLI SDK",
   "license": "Apache-2.0",
   "repository": {

packages/test-utils/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@google/gemini-cli-test-utils",
-  "version": "0.55.1",
+  "version": "0.56.0-nightly.20260806.g761f604c1",
   "private": true,
   "main": "src/index.ts",
   "license": "Apache-2.0",

packages/vscode-ide-companion/package.json

@@ -2,7 +2,7 @@
   "name": "gemini-cli-vscode-ide-companion",
   "displayName": "Gemini CLI Companion",
   "description": "Enable Gemini CLI with direct access to your IDE workspace.",
-  "version": "0.55.1",
+  "version": "0.56.0-nightly.20260806.g761f604c1",
   "publisher": "google",
   "icon": "assets/icon.png",
   "repository": {