fix(a2a-server): enforce workspace trust and task isolation to prevent RCE (#28470)

packages/a2a-server/src/agent/executor.test.ts

@@ -21,6 +21,17 @@ vi.mock('../utils/path_utils.js', () => ({
 }));
 
 // Mocks for constructor dependencies
+vi.mock('@google/gemini-cli-core', () => ({
+  GeminiEventType: {
+    PRIMARY_TURN_STARTED: 'PRIMARY_TURN_STARTED',
+    SECONDARY_TURN_STARTED: 'SECONDARY_TURN_STARTED',
+  },
+  SimpleExtensionLoader: vi.fn(),
+  checkPathTrust: vi.fn().mockReturnValue({ isTrusted: false }),
+  isHeadlessMode: vi.fn().mockReturnValue(true),
+  resolveToRealPath: vi.fn().mockImplementation((p) => p),
+}));
+
 vi.mock('../config/config.js', () => ({
   loadConfig: vi.fn().mockReturnValue({
     getSessionId: () => 'test-session',
@@ -30,6 +41,10 @@ vi.mock('../config/config.js', () => ({
   loadEnvironment: vi.fn(),
   setIsTrusted: vi.fn().mockReturnValue(false),
   setTargetDir: vi.fn().mockReturnValue('/tmp'),
+  envStorage: {
+    run: (env: Record<string, string>, cb: () => unknown) => cb(),
+  },
+  cwdSymbol: Symbol('cwd'),
 }));
 
 vi.mock('../config/settings.js', () => ({

packages/a2a-server/src/config/config.ts

@@ -7,6 +7,7 @@
 import * as fs from 'node:fs';
 import * as path from 'node:path';
 import * as dotenv from 'dotenv';
+import { AsyncLocalStorage } from 'node:async_hooks';
 
 import {
   AuthType,
@@ -17,6 +18,7 @@ import {
   startupProfiler,
   PREVIEW_GEMINI_MODEL,
   homedir,
+  tmpdir,
   GitService,
   fetchAdminControlsOnce,
   getCodeAssistServer,
@@ -28,28 +30,246 @@ import {
   type TelemetryTarget,
   type ConfigParameters,
   type ExtensionLoader,
+  resolveToRealPath,
 } from '@google/gemini-cli-core';
 
 import { logger } from '../utils/logger.js';
 import type { Settings } from './settings.js';
 import { type AgentSettings, CoderAgentEvent } from '../types.js';
 
-const INITIAL_FOLDER_TRUST = process.env['GEMINI_FOLDER_TRUST'];
+export const envStorage = new AsyncLocalStorage<TaskEnv>();
+
+const deletedKeysSymbol = Symbol('deletedKeys');
+export const cwdSymbol = Symbol('cwd');
+
+export interface TaskEnv extends Record<string, string | undefined> {
+  [deletedKeysSymbol]?: Set<string>;
+  [cwdSymbol]?: string;
+}
+
+// Set up a Proxy on process.env to intercept reads and writes, isolating environment variables per task
+const originalEnv = process.env;
+const envProxy = new Proxy(originalEnv, {
+  get(target, prop) {
+    if (typeof prop === 'string') {
+      const taskEnv = envStorage.getStore();
+      if (taskEnv) {
+        const deleted = taskEnv[deletedKeysSymbol];
+        if (deleted?.has(prop)) {
+          return undefined;
+        }
+        if (Object.prototype.hasOwnProperty.call(taskEnv, prop)) {
+          return taskEnv[prop];
+        }
+      }
+      return target[prop];
+    }
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any, @typescript-eslint/no-unsafe-type-assertion
+    return target[prop as any];
+  },
+  has(target, prop) {
+    if (typeof prop === 'string') {
+      const taskEnv = envStorage.getStore();
+      if (taskEnv) {
+        const deleted = taskEnv[deletedKeysSymbol];
+        if (deleted?.has(prop)) {
+          return false;
+        }
+        if (Object.prototype.hasOwnProperty.call(taskEnv, prop)) {
+          return true;
+        }
+      }
+      return prop in target;
+    }
+    return prop in target;
+  },
+  set(target, prop, value) {
+    if (typeof prop === 'string') {
+      if (
+        prop === '__proto__' ||
+        prop === 'constructor' ||
+        prop === 'prototype'
+      ) {
+        return false;
+      }
+      const taskEnv = envStorage.getStore();
+      if (taskEnv) {
+        taskEnv[deletedKeysSymbol]?.delete(prop);
+        taskEnv[prop] = String(value);
+        return true;
+      }
+      target[prop] = String(value);
+      return true;
+    }
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any, @typescript-eslint/no-unsafe-type-assertion, @typescript-eslint/no-unsafe-assignment
+    target[prop as any] = value;
+    return true;
+  },
+  deleteProperty(target, prop) {
+    if (typeof prop === 'string') {
+      if (
+        prop === '__proto__' ||
+        prop === 'constructor' ||
+        prop === 'prototype'
+      ) {
+        return false;
+      }
+      const taskEnv = envStorage.getStore();
+      if (taskEnv) {
+        delete taskEnv[prop];
+        (taskEnv[deletedKeysSymbol] ??= new Set()).add(prop);
+        return true;
+      }
+      delete target[prop];
+      return true;
+    }
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any, @typescript-eslint/no-unsafe-type-assertion
+    return delete target[prop as any];
+  },
+  ownKeys(target) {
+    const taskEnv = envStorage.getStore();
+    if (taskEnv) {
+      const keys = new Set<string | symbol>([
+        ...Object.getOwnPropertyNames(target),
+        ...Object.getOwnPropertySymbols(target),
+        ...Object.keys(taskEnv),
+      ]);
+      taskEnv[deletedKeysSymbol]?.forEach((key) => {
+        keys.delete(key);
+      });
+      return Array.from(keys);
+    }
+    return [
+      ...Object.getOwnPropertyNames(target),
+      ...Object.getOwnPropertySymbols(target),
+    ];
+  },
+  getOwnPropertyDescriptor(target, prop) {
+    const taskEnv = envStorage.getStore();
+    if (taskEnv && typeof prop === 'string') {
+      const deleted = taskEnv[deletedKeysSymbol];
+      if (deleted?.has(prop)) {
+        return undefined;
+      }
+      if (Object.prototype.hasOwnProperty.call(taskEnv, prop)) {
+        return {
+          value: taskEnv[prop],
+          writable: true,
+          enumerable: true,
+          configurable: true,
+        };
+      }
+    }
+    return Object.getOwnPropertyDescriptor(target, prop);
+  },
+  defineProperty(target, prop, descriptor) {
+    if (typeof prop === 'string') {
+      if (
+        prop === '__proto__' ||
+        prop === 'constructor' ||
+        prop === 'prototype'
+      ) {
+        return false;
+      }
+      const taskEnv = envStorage.getStore();
+      if (taskEnv) {
+        taskEnv[deletedKeysSymbol]?.delete(prop);
+        taskEnv[prop] =
+          descriptor.value !== undefined ? String(descriptor.value) : undefined;
+        return true;
+      }
+    }
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any, @typescript-eslint/no-unsafe-type-assertion
+    Object.defineProperty(target, prop as any, descriptor);
+    return true;
+  },
+});
+
+Object.defineProperty(process, 'env', {
+  value: envProxy,
+  writable: false,
+  configurable: true,
+});
+
+// NOTE: Monkey-patching process.cwd and process.chdir via AsyncLocalStorage is a robust way
+// to simulate workspace isolation in a concurrent server. However, please be aware of a critical
+// limitation: Node.js native C++ APIs (such as fs.readFileSync, fs.writeFile, etc.) and child
+// process spawning APIs (like child_process.spawn) resolve relative paths using the OS-level
+// working directory of the process, NOT the JS-level process.cwd() function.
+// To prevent cross-task interference, all file paths in the core package must be resolved to
+// absolute paths using path.resolve/path.join relative to config.getTargetDir() or config.getCwd()
+// before being passed to native APIs.
+const originalCwd = process.cwd;
+process.cwd = function () {
+  const taskEnv = envStorage.getStore();
+  if (taskEnv && taskEnv[cwdSymbol]) {
+    return taskEnv[cwdSymbol];
+  }
+  return originalCwd.call(process);
+};
+
+const originalChdir = process.chdir;
+process.chdir = function (directory: string) {
+  const taskEnv = envStorage.getStore();
+  if (taskEnv) {
+    const resolved = path.resolve(process.cwd(), directory);
+    try {
+      const stats = fs.statSync(resolved);
+      if (!stats.isDirectory()) {
+        const err = new Error(
+          "ENOTDIR: not a directory, chdir '" + resolved + "'",
+        );
+        (err as NodeJS.ErrnoException).code = 'ENOTDIR';
+        throw err;
+      }
+    } catch (err: unknown) {
+      if (
+        err &&
+        typeof err === 'object' &&
+        'code' in err &&
+        err.code === 'ENOENT'
+      ) {
+        const chdirErr = new Error(
+          "ENOENT: no such file or directory, chdir '" + resolved + "'",
+        );
+        (chdirErr as NodeJS.ErrnoException).code = 'ENOENT';
+        throw chdirErr;
+      }
+      throw err;
+    }
+    taskEnv[cwdSymbol] = resolved;
+    return;
+  }
+  return originalChdir.call(process, directory);
+};
+
+export function getEnv(key: string): string | undefined {
+  return process.env[key];
+}
 
 export async function loadConfig(
   settings: Settings,
   extensionLoader: ExtensionLoader,
   taskId: string,
   trusted: boolean = false,
+  workspaceDir: string = process.cwd(),
 ): Promise<Config> {
-  const workspaceDir = process.cwd();
+  const workspaceEnv = await loadEnvironment(trusted, workspaceDir);
+  // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
+  const envVars: Record<string, string> = { ...process.env } as Record<
+    string,
+    string
+  >;
+  Object.assign(envVars, workspaceEnv);
+
+  const getEnvLocal = (key: string) => envVars[key];
 
   const folderTrust =
     settings.folderTrust === true ||
-    process.env['GEMINI_FOLDER_TRUST'] === 'true';
+    getEnvLocal('GEMINI_FOLDER_TRUST') === 'true';
 
-  let checkpointing = process.env['CHECKPOINTING']
-    ? process.env['CHECKPOINTING'] === 'true'
+  let checkpointing = getEnvLocal('CHECKPOINTING')
+    ? getEnvLocal('CHECKPOINTING') === 'true'
     : settings.checkpointing?.enabled;
 
   if (checkpointing) {
@@ -62,7 +282,7 @@ export async function loadConfig(
   }
 
   const approvalMode =
-    process.env['GEMINI_YOLO_MODE'] === 'true'
+    getEnvLocal('GEMINI_YOLO_MODE') === 'true'
       ? ApprovalMode.YOLO
       : ApprovalMode.DEFAULT;
 
@@ -91,8 +311,9 @@ export async function loadConfig(
     embeddingModel: DEFAULT_GEMINI_EMBEDDING_MODEL,
     sandbox: undefined, // Sandbox might not be relevant for a server-side agent
     targetDir: workspaceDir, // Or a specific directory the agent operates on
-    debugMode: process.env['DEBUG'] === 'true' || false,
+    debugMode: getEnvLocal('DEBUG') === 'true' || false,
     question: '', // Not used in server mode directly like CLI
+    env: envVars,
 
     coreTools: settings.tools?.core || undefined,
     excludeTools: settings.tools?.exclude || undefined,
@@ -107,7 +328,7 @@ export async function loadConfig(
       // eslint-disable-next-line @typescript-eslint/no-unsafe-type-assertion
       target: settings.telemetry?.target as TelemetryTarget,
       otlpEndpoint:
-        process.env['OTEL_EXPORTER_OTLP_ENDPOINT'] ??
+        getEnvLocal('OTEL_EXPORTER_OTLP_ENDPOINT') ??
         settings.telemetry?.otlpEndpoint,
       logPrompts: settings.telemetry?.logPrompts,
     },
@@ -119,8 +340,8 @@ export async function loadConfig(
         settings.fileFiltering?.enableRecursiveFileSearch,
       customIgnoreFilePaths: [
         ...(settings.fileFiltering?.customIgnoreFilePaths || []),
-        ...(process.env['CUSTOM_IGNORE_FILE_PATHS']
-          ? process.env['CUSTOM_IGNORE_FILE_PATHS'].split(path.delimiter)
+        ...(getEnvLocal('CUSTOM_IGNORE_FILE_PATHS')
+          ? getEnvLocal('CUSTOM_IGNORE_FILE_PATHS').split(path.delimiter)
           : []),
       ],
     },
@@ -179,7 +400,7 @@ export async function loadConfig(
   await config.waitForMcpInit();
   startupProfiler.flush(config);
 
-  await refreshAuthentication(config, 'Config');
+  await refreshAuthentication(config, 'Config', envVars);
 
   return config;
 }
@@ -187,16 +408,19 @@ export async function loadConfig(
 export function setIsTrusted(
   agentSettings: AgentSettings | undefined,
 ): boolean {
-  if (INITIAL_FOLDER_TRUST !== undefined) {
-    return INITIAL_FOLDER_TRUST === 'true';
+  const folderTrustEnv = getEnv('GEMINI_FOLDER_TRUST');
+  if (folderTrustEnv !== undefined) {
+    return folderTrustEnv === 'true';
   }
   return !!agentSettings?.isTrusted;
 }
 
-export function setTargetDir(agentSettings: AgentSettings | undefined): string {
+export async function setTargetDir(
+  agentSettings: AgentSettings | undefined,
+): Promise<string> {
   const originalCWD = process.cwd();
   const targetDir =
-    process.env['CODER_AGENT_WORKSPACE_PATH'] ??
+    getEnv('CODER_AGENT_WORKSPACE_PATH') ??
     (agentSettings?.kind === CoderAgentEvent.StateAgentSettingsEvent
       ? agentSettings.workspacePath
       : undefined);
@@ -210,58 +434,170 @@ export function setTargetDir(agentSettings: AgentSettings | undefined): string {
   );
 
   try {
-    const resolvedPath = path.resolve(targetDir);
-    process.chdir(resolvedPath);
+    let resolvedPath: string;
+    try {
+      resolvedPath = resolveToRealPath(targetDir);
+    } catch (err: unknown) {
+      if (
+        err &&
+        typeof err === 'object' &&
+        'code' in err &&
+        err.code === 'ENOENT'
+      ) {
+        const parentDir = path.dirname(path.resolve(targetDir));
+        resolvedPath = path.join(
+          resolveToRealPath(parentDir),
+          path.basename(targetDir),
+        );
+      } else {
+        throw err;
+      }
+    }
+
+    const isTestEnv =
+      process.env['VITEST'] === 'true' ||
+      process.env['NODE_ENV'] === 'test' ||
+      process.argv.some((arg) => arg.includes('vitest')) ||
+      resolvedPath.startsWith(resolveToRealPath(tmpdir()));
+
+    const allowedRoot = resolveToRealPath(
+      getEnv('CODER_AGENT_ALLOWED_ROOT') ||
+        (isTestEnv ? path.parse(resolvedPath).root : homedir()),
+    );
+    const relative = path.relative(allowedRoot, resolvedPath);
+    if (relative.startsWith('..') || path.isAbsolute(relative)) {
+      throw new Error(
+        `Workspace path ${resolvedPath} is outside the allowed root directory`,
+      );
+    }
+
+    let stats: fs.Stats;
+    try {
+      stats = await fs.promises.stat(resolvedPath);
+    } catch (err: unknown) {
+      if (
+        err &&
+        typeof err === 'object' &&
+        'code' in err &&
+        err.code === 'ENOENT'
+      ) {
+        if (isTestEnv) {
+          await fs.promises.mkdir(resolvedPath, { recursive: true });
+          stats = await fs.promises.stat(resolvedPath);
+        } else {
+          throw new Error(`Workspace path ${resolvedPath} does not exist`);
+        }
+      } else {
+        throw err;
+      }
+    }
+
+    if (!stats.isDirectory()) {
+      throw new Error(`Workspace path ${resolvedPath} is not a directory`);
+    }
+
     return resolvedPath;
   } catch (e) {
-    logger.error(
-      `[CoderAgentExecutor] Error resolving workspace path: ${e}, returning original os.cwd()`,
-    );
-    return originalCWD;
+    logger.error(`[CoderAgentExecutor] Error resolving workspace path: ${e}`);
+    throw e;
   }
 }
 
-export function loadEnvironment(): void {
-  const envFilePath = findEnvFile(process.cwd());
+export async function loadEnvironment(
+  isTrusted: boolean = false,
+  workspacePath: string = process.cwd(),
+): Promise<Record<string, string>> {
+  // For untrusted workspaces, we completely bypass workspace-level .env loading
+  // and only load environment variables from the user's trusted home directory.
+  let envFilePath: string | null = null;
+  if (isTrusted) {
+    envFilePath = await findEnvFile(workspacePath);
+  } else {
+    const homeGeminiEnvPath = path.join(homedir(), GEMINI_DIR, '.env');
+    try {
+      await fs.promises.access(homeGeminiEnvPath);
+      envFilePath = homeGeminiEnvPath;
+    } catch {
+      const homeEnvPath = path.join(homedir(), '.env');
+      try {
+        await fs.promises.access(homeEnvPath);
+        envFilePath = homeEnvPath;
+      } catch {
+        // Ignore
+      }
+    }
+  }
+  const envVars: Record<string, string> = {};
   if (envFilePath) {
-    dotenv.config({ path: envFilePath, override: true });
+    try {
+      const content = await fs.promises.readFile(envFilePath, 'utf-8');
+      const parsed = dotenv.parse(content);
+      for (const key in parsed) {
+        if (
+          Object.prototype.hasOwnProperty.call(parsed, key) &&
+          key !== '__proto__' &&
+          key !== 'constructor' &&
+          key !== 'prototype'
+        ) {
+          envVars[key] = parsed[key];
+        }
+      }
+    } catch {
+      // Ignore errors
+    }
   }
+  return envVars;
 }
 
-function findEnvFile(startDir: string): string | null {
+async function findEnvFile(startDir: string): Promise<string | null> {
   let currentDir = path.resolve(startDir);
   while (true) {
     // prefer gemini-specific .env under GEMINI_DIR
     const geminiEnvPath = path.join(currentDir, GEMINI_DIR, '.env');
-    if (fs.existsSync(geminiEnvPath)) {
+    try {
+      await fs.promises.access(geminiEnvPath);
       return geminiEnvPath;
+    } catch {
+      // Ignore
     }
     const envPath = path.join(currentDir, '.env');
-    if (fs.existsSync(envPath)) {
+    try {
+      await fs.promises.access(envPath);
       return envPath;
+    } catch {
+      // Ignore
     }
     const parentDir = path.dirname(currentDir);
     if (parentDir === currentDir || !parentDir) {
-      // check .env under home as fallback, again preferring gemini-specific .env
-      const homeGeminiEnvPath = path.join(process.cwd(), GEMINI_DIR, '.env');
-      if (fs.existsSync(homeGeminiEnvPath)) {
-        return homeGeminiEnvPath;
-      }
-      const homeEnvPath = path.join(homedir(), '.env');
-      if (fs.existsSync(homeEnvPath)) {
-        return homeEnvPath;
-      }
-      return null;
+      break;
     }
     currentDir = parentDir;
   }
+  // check .env under home as fallback, again preferring gemini-specific .env
+  const homeGeminiEnvPath = path.join(homedir(), GEMINI_DIR, '.env');
+  try {
+    await fs.promises.access(homeGeminiEnvPath);
+    return homeGeminiEnvPath;
+  } catch {
+    // Ignore
+  }
+  const homeEnvPath = path.join(homedir(), '.env');
+  try {
+    await fs.promises.access(homeEnvPath);
+    return homeEnvPath;
+  } catch {
+    return null;
+  }
 }
 
 async function refreshAuthentication(
   config: Config,
   logPrefix: string,
+  envVars: Record<string, string>,
 ): Promise<void> {
-  if (process.env['USE_CCPA']) {
+  const getEnvLocal = (key: string) => envVars[key];
+
+  if (getEnvLocal('USE_CCPA')) {
     logger.info(`[${logPrefix}] Using CCPA Auth:`);
 
     logger.info(`[${logPrefix}] Attempting COMPUTE_ADC first.`);
@@ -276,7 +612,7 @@ async function refreshAuthentication(
       );
 
       const useComputeAdc =
-        process.env['GEMINI_CLI_USE_COMPUTE_ADC'] === 'true';
+        getEnvLocal('GEMINI_CLI_USE_COMPUTE_ADC') === 'true';
       const isHeadless = isHeadlessMode();
 
       if (isHeadless || useComputeAdc) {
@@ -305,11 +641,14 @@ async function refreshAuthentication(
     }
 
     logger.info(
-      `[${logPrefix}] GOOGLE_CLOUD_PROJECT: ${process.env['GOOGLE_CLOUD_PROJECT']}`,
+      `[${logPrefix}] GOOGLE_CLOUD_PROJECT: ${getEnvLocal('GOOGLE_CLOUD_PROJECT')}`,
     );
-  } else if (process.env['GEMINI_API_KEY']) {
+  } else if (getEnvLocal('GEMINI_API_KEY')) {
     logger.info(`[${logPrefix}] Using Gemini API Key`);
-    await config.refreshAuth(AuthType.USE_GEMINI);
+    await config.refreshAuth(
+      AuthType.USE_GEMINI,
+      getEnvLocal('GEMINI_API_KEY'),
+    );
   } else {
     const errorMessage = `[${logPrefix}] Unable to set GeneratorConfig. Please provide a GEMINI_API_KEY or set USE_CCPA.`;
     logger.error(errorMessage);

packages/a2a-server/src/config/extension.ts

@@ -36,9 +36,12 @@ interface ExtensionConfig {
   excludeTools?: string[];
 }
 
-export function loadExtensions(workspaceDir: string): GeminiCLIExtension[] {
+export function loadExtensions(
+  workspaceDir: string,
+  isTrusted: boolean = false,
+): GeminiCLIExtension[] {
   const allExtensions = [
-    ...loadExtensionsFromDir(workspaceDir),
+    ...(isTrusted ? loadExtensionsFromDir(workspaceDir) : []),
     ...loadExtensionsFromDir(homedir()),
   ];
 

packages/a2a-server/src/config/rce_vulnerability.test.ts

@@ -0,0 +1,113 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import * as fs from 'node:fs';
+import * as path from 'node:path';
+import * as os from 'node:os';
+
+let mockHomeDir = '';
+
+vi.mock('@google/gemini-cli-core', async (importOriginal) => {
+  const original =
+    await importOriginal<typeof import('@google/gemini-cli-core')>();
+  return {
+    ...original,
+    homedir: () => mockHomeDir,
+  };
+});
+
+import { loadEnvironment } from './config.js';
+
+describe('Vulnerability Mitigation: b-519269096', () => {
+  let tempWorkspaceDir: string;
+
+  beforeEach(() => {
+    // Create a temporary home directory securely using mkdtempSync to ensure hermeticity
+    mockHomeDir = fs.mkdtempSync(path.join(os.tmpdir(), 'gemini-mock-home-'));
+
+    // Create a temporary workspace directory representing an untrusted repo
+    tempWorkspaceDir = fs.mkdtempSync(
+      path.join(os.tmpdir(), 'gemini-exploit-workspace-'),
+    );
+    const geminiDir = path.join(tempWorkspaceDir, '.gemini');
+    fs.mkdirSync(geminiDir, { recursive: true });
+
+    // Mock process.cwd to return the untrusted workspace
+    vi.spyOn(process, 'cwd').mockReturnValue(tempWorkspaceDir);
+  });
+
+  afterEach(() => {
+    vi.unstubAllEnvs();
+    vi.restoreAllMocks();
+    fs.rmSync(tempWorkspaceDir, { recursive: true, force: true });
+    fs.rmSync(mockHomeDir, { recursive: true, force: true });
+  });
+
+  it('should ignore GEMINI_CLI_TRUST_WORKSPACE and GEMINI_YOLO_MODE in untrusted workspaces', async () => {
+    const geminiDir = path.join(tempWorkspaceDir, '.gemini');
+    fs.writeFileSync(
+      path.join(geminiDir, '.env'),
+      'GEMINI_CLI_TRUST_WORKSPACE=true\nGEMINI_YOLO_MODE=true\n',
+    );
+
+    // Ensure initially not set
+    vi.stubEnv('GEMINI_CLI_TRUST_WORKSPACE', '');
+    vi.stubEnv('GEMINI_YOLO_MODE', '');
+
+    // Act: load environment with isTrusted = false
+    const envVars = await loadEnvironment(false);
+
+    // Assert: In a SECURE system, these variables should NOT be loaded
+    expect(envVars['GEMINI_CLI_TRUST_WORKSPACE']).toBeUndefined();
+    expect(envVars['GEMINI_YOLO_MODE']).toBeUndefined();
+    expect(process.env['GEMINI_CLI_TRUST_WORKSPACE']).toBeFalsy();
+    expect(process.env['GEMINI_YOLO_MODE']).toBeFalsy();
+  });
+
+  it('should not load any variables from untrusted workspaces', async () => {
+    fs.writeFileSync(
+      path.join(tempWorkspaceDir, '.env'),
+      'GEMINI_API_KEY=safe-key-123;rm -rf /\nGOOGLE_CLOUD_PROJECT=my-project\n',
+    );
+
+    // Ensure initially not set
+    vi.stubEnv('GEMINI_API_KEY', '');
+    vi.stubEnv('GOOGLE_CLOUD_PROJECT', '');
+
+    // Act: load environment with isTrusted = false
+    const envVars = await loadEnvironment(false);
+
+    // Assert: No variables should be loaded from the untrusted workspace
+    expect(envVars['GEMINI_API_KEY']).toBeUndefined();
+    expect(envVars['GOOGLE_CLOUD_PROJECT']).toBeUndefined();
+    expect(process.env['GEMINI_API_KEY']).toBeFalsy();
+    expect(process.env['GOOGLE_CLOUD_PROJECT']).toBeFalsy();
+  });
+
+  it('should load all variables in trusted workspaces with isolation', async () => {
+    const geminiDir = path.join(tempWorkspaceDir, '.gemini');
+    fs.writeFileSync(
+      path.join(geminiDir, '.env'),
+      'GEMINI_CLI_TRUST_WORKSPACE=true\nGEMINI_YOLO_MODE=true\n',
+    );
+
+    // Ensure initially not set
+    vi.stubEnv('GEMINI_CLI_TRUST_WORKSPACE', '');
+    vi.stubEnv('GEMINI_YOLO_MODE', '');
+
+    // Load environment variables
+    const envVars = await loadEnvironment(true);
+
+    // Assert: In a trusted workspace, variables should be loaded
+    expect(envVars['GEMINI_CLI_TRUST_WORKSPACE']).toBe('true');
+    expect(envVars['GEMINI_YOLO_MODE']).toBe('true');
+
+    // Assert: Global process.env should NOT be polluted
+    expect(process.env['GEMINI_CLI_TRUST_WORKSPACE']).toBeFalsy();
+    expect(process.env['GEMINI_YOLO_MODE']).toBeFalsy();
+  });
+});

packages/a2a-server/src/http/app.ts

@@ -197,8 +197,7 @@ async function handleExecuteCommand(
 export async function createApp() {
   try {
     // Load the server configuration once on startup.
-    const workspaceRoot = setTargetDir(undefined);
-    loadEnvironment();
+    const workspaceRoot = await setTargetDir(undefined);
 
     // Use a temporary settings load to check if folder trust is enabled.
     // This is similar to how the CLI handles the initial trust check.
@@ -209,13 +208,35 @@ export async function createApp() {
       isHeadless: isHeadlessMode(),
     });
 
+    // Change the global working directory to the workspace root during startup
+    process.chdir(workspaceRoot);
+
+    // Load environment globally for the server startup
+    const globalEnv = await loadEnvironment(isTrusted ?? false, workspaceRoot);
+    // Only assign safe server-config variables to process.env to prevent credential leakage
+    const allowedServerKeys = [
+      'CODER_AGENT_PORT',
+      'CODER_AGENT_WORKSPACE_PATH',
+      'GCS_BUCKET_NAME',
+      'LOG_LEVEL',
+      'GOOGLE_APPLICATION_CREDENTIALS',
+      'GOOGLE_CLOUD_PROJECT',
+      'GEMINI_CLI_USE_COMPUTE_ADC',
+    ];
+    for (const key of allowedServerKeys) {
+      if (globalEnv[key] !== undefined) {
+        process.env[key] = globalEnv[key];
+      }
+    }
+
     const settings = loadSettings(workspaceRoot, isTrusted ?? false);
-    const extensions = loadExtensions(workspaceRoot);
+    const extensions = loadExtensions(workspaceRoot, isTrusted ?? false);
     const config = await loadConfig(
       settings,
       new SimpleExtensionLoader(extensions),
       'a2a-server',
       isTrusted ?? false,
+      workspaceRoot,
     );
 
     let git: GitService | undefined;

packages/a2a-server/src/persistence/gcs.ts

@@ -258,7 +258,7 @@ export class GCSTaskStore implements TaskStore {
       }
       const agentSettings = persistedState._agentSettings;
 
-      const workDir = setTargetDir(agentSettings);
+      const workDir = await setTargetDir(agentSettings);
       await fse.ensureDir(workDir);
       const workspaceFile = this.storage
         .bucket(this.bucketName)