diff --git a/src/utils/execFileNoThrow.test.ts b/src/utils/execFileNoThrow.test.ts
new file mode 100644
index 00000000..9fff427e
--- /dev/null
+++ b/src/utils/execFileNoThrow.test.ts
@@ -0,0 +1,25 @@
+import { expect, test } from 'bun:test'
+import { execFileNoThrowWithCwd } from './execFileNoThrow.js'
+
+test('execFileNoThrowWithCwd rejects shell-like executable names', async () => {
+  const result = await execFileNoThrowWithCwd('openclaude && whoami', [])
+
+  expect(result.code).toBe(1)
+  expect(result.error).toContain('Unsafe executable')
+})
+
+test('execFileNoThrowWithCwd rejects cwd values with control characters', async () => {
+  const result = await execFileNoThrowWithCwd(process.execPath, ['--version'], {
+    cwd: 'C:\\repo\nmalicious',
+  })
+
+  expect(result.code).toBe(1)
+  expect(result.error).toContain('Unsafe working directory')
+})
+
+test('execFileNoThrowWithCwd rejects arguments with control characters', async () => {
+  const result = await execFileNoThrowWithCwd(process.execPath, ['--version\nmalicious'])
+
+  expect(result.code).toBe(1)
+  expect(result.error).toContain('Unsafe argument')
+})
diff --git a/src/utils/execFileNoThrow.ts b/src/utils/execFileNoThrow.ts
index cc71fb8d..3b0c404d 100644
--- a/src/utils/execFileNoThrow.ts
+++ b/src/utils/execFileNoThrow.ts
@@ -3,6 +3,7 @@
 // By using execa, Windows automatically gets shell escaping + BAT / CMD handling
 
 import { type ExecaError, execa } from 'execa'
+import path from 'node:path'
 import { getCwd } from '../utils/cwd.js'
 import { logError } from './log.js'
 
@@ -59,6 +60,46 @@ type ExecaResultWithError = {
   signal?: string
 }
 
+const CONTROL_CHAR_PATTERN = /[\0\r\n]/
+const SAFE_BARE_EXECUTABLE_PATTERN = /^[A-Za-z0-9_.-]+$/
+
+function hasPathSyntax(value: string): boolean {
+  return value.includes(path.sep) || value.includes('/') || path.isAbsolute(value)
+}
+
+function validateExecutable(file: string): string | null {
+  const normalized = file.trim()
+  if (!normalized) {
+    return 'Unsafe executable: empty command'
+  }
+  if (CONTROL_CHAR_PATTERN.test(normalized)) {
+    return 'Unsafe executable: control characters are not allowed'
+  }
+  if (!hasPathSyntax(normalized) && !SAFE_BARE_EXECUTABLE_PATTERN.test(normalized)) {
+    return 'Unsafe executable: bare command names may only contain letters, numbers, ".", "_" and "-"'
+  }
+  return null
+}
+
+function validateArgs(args: string[]): string | null {
+  for (const arg of args) {
+    if (CONTROL_CHAR_PATTERN.test(arg)) {
+      return 'Unsafe argument: control characters are not allowed'
+    }
+  }
+  return null
+}
+
+function validateWorkingDirectory(cwd: string | undefined): string | null {
+  if (!cwd) {
+    return null
+  }
+  if (CONTROL_CHAR_PATTERN.test(cwd)) {
+    return 'Unsafe working directory: control characters are not allowed'
+  }
+  return null
+}
+
 /**
  * Extracts a human-readable error message from an execa result.
  *
@@ -103,6 +144,21 @@ export function execFileNoThrowWithCwd(
     maxBuffer: 1_000_000,
   },
 ): Promise<{ stdout: string; stderr: string; code: number; error?: string }> {
+  const executableError = validateExecutable(file)
+  if (executableError) {
+    return Promise.resolve({ stdout: '', stderr: '', code: 1, error: executableError })
+  }
+
+  const argsError = validateArgs(args)
+  if (argsError) {
+    return Promise.resolve({ stdout: '', stderr: '', code: 1, error: argsError })
+  }
+
+  const cwdError = validateWorkingDirectory(finalCwd)
+  if (cwdError) {
+    return Promise.resolve({ stdout: '', stderr: '', code: 1, error: cwdError })
+  }
+
   return new Promise(resolve => {
     // Use execa for cross-platform .bat/.cmd compatibility on Windows
     execa(file, args, {
diff --git a/vscode-extension/openclaude-vscode/src/state.js b/vscode-extension/openclaude-vscode/src/state.js
index 9f4e13f7..e17a12eb 100644
--- a/vscode-extension/openclaude-vscode/src/state.js
+++ b/vscode-extension/openclaude-vscode/src/state.js
@@ -109,6 +109,19 @@ function isLocalBaseUrl(baseUrl) {
   }
 }
 
+function getHostname(baseUrl) {
+  const normalized = asNonEmptyString(baseUrl);
+  if (!normalized) {
+    return null;
+  }
+
+  try {
+    return new URL(normalized).hostname.toLowerCase();
+  } catch {
+    return null;
+  }
+}
+
 function resolveCommandCheckPath(command, workspacePath) {
   const normalized = asNonEmptyString(command);
   if (!normalized) {
@@ -241,6 +254,7 @@ function hasCodexAlias(model) {
 function getOpenAICompatibleLabel(baseUrl, model) {
   const normalizedBaseUrl = (asNonEmptyString(baseUrl) || '').toLowerCase();
   const normalizedModel = (asNonEmptyString(model) || '').toLowerCase();
+  const hostname = getHostname(baseUrl);
 
   if (hasCodexBaseUrl(baseUrl) || (!baseUrl && hasCodexAlias(model))) {
     return 'Codex';
@@ -278,7 +292,7 @@ function getOpenAICompatibleLabel(baseUrl, model) {
     return 'Azure OpenAI';
   }
 
-  if (normalizedBaseUrl.includes('api.openai.com') || !normalizedBaseUrl) {
+  if (hostname === 'api.openai.com' || !normalizedBaseUrl) {
     return 'OpenAI';
   }
 
diff --git a/vscode-extension/openclaude-vscode/src/state.test.js b/vscode-extension/openclaude-vscode/src/state.test.js
index 5495df59..b3e0bcb9 100644
--- a/vscode-extension/openclaude-vscode/src/state.test.js
+++ b/vscode-extension/openclaude-vscode/src/state.test.js
@@ -158,6 +158,44 @@ test('describeProviderState reports LM Studio from openai profile base url', ()
   );
 });
 
+test('describeProviderState does not treat substring-matched OpenAI hosts as OpenAI', () => {
+  assert.deepEqual(
+    describeProviderState({
+      shimEnabled: false,
+      env: {
+        CLAUDE_CODE_USE_OPENAI: '1',
+        OPENAI_BASE_URL: 'https://evil.example/path/api.openai.com/v1',
+        OPENAI_MODEL: 'gpt-4o',
+      },
+      profile: null,
+    }),
+    {
+      label: 'OpenAI-compatible',
+      detail: 'gpt-4o',
+      source: 'env',
+    },
+  );
+});
+
+test('describeProviderState reports OpenAI when the parsed host is api.openai.com', () => {
+  assert.deepEqual(
+    describeProviderState({
+      shimEnabled: false,
+      env: {
+        CLAUDE_CODE_USE_OPENAI: '1',
+        OPENAI_BASE_URL: 'https://api.openai.com/v1',
+        OPENAI_MODEL: 'gpt-4o',
+      },
+      profile: null,
+    }),
+    {
+      label: 'OpenAI',
+      detail: 'gpt-4o',
+      source: 'env',
+    },
+  );
+});
+
 test('describeProviderState reports environment-backed provider details', () => {
   assert.deepEqual(
     describeProviderState({