diff --git a/packages/remote-control-server/src/config.ts b/packages/remote-control-server/src/config.ts
index cd7716032..3469bb6eb 100644
--- a/packages/remote-control-server/src/config.ts
+++ b/packages/remote-control-server/src/config.ts
@@ -1,7 +1,7 @@
 export const config = {
   version: process.env.RCS_VERSION || "0.1.0",
   port: parseInt(process.env.RCS_PORT || "3000"),
-  host: process.env.RCS_HOST || "0.0.0.0",
+  host: process.env.RCS_HOST || "127.0.0.1",
   apiKeys: (process.env.RCS_API_KEYS || "").split(",").filter(Boolean),
   baseUrl: process.env.RCS_BASE_URL || "",
   pollTimeout: parseInt(process.env.RCS_POLL_TIMEOUT || "8"),
diff --git a/packages/remote-control-server/src/index.ts b/packages/remote-control-server/src/index.ts
index 309f29889..d6bad0684 100644
--- a/packages/remote-control-server/src/index.ts
+++ b/packages/remote-control-server/src/index.ts
@@ -25,10 +25,25 @@ import webEnvironments from "./routes/web/environments";
 console.log("[RCS] In-memory store ready (no SQLite)");
 
 const app = new Hono();
+const port = config.port;
+const host = config.host;
+
+const allowedWebOrigins = [
+  `http://localhost:${port}`,
+  `http://127.0.0.1:${port}`,
+  config.baseUrl,
+].filter(Boolean);
 
 // Middleware
 app.use("*", logger());
-app.use("/web/*", cors());
+app.use(
+  "/web/*",
+  cors({
+    origin: (origin) =>
+      allowedWebOrigins.includes(origin) ? origin : undefined,
+    credentials: true,
+  }),
+);
 
 // Health check
 app.get("/health", (c) => c.json({ status: "ok", version: config.version }));
@@ -70,9 +85,6 @@ app.route("/web", webSessions);
 app.route("/web", webControl);
 app.route("/web", webEnvironments);
 
-const port = config.port;
-const host = config.host;
-
 console.log(`[RCS] Remote Control Server starting on ${host}:${port}`);
 console.log("[RCS] API key configuration loaded");
 console.log(`[RCS] Base URL: ${config.baseUrl || `http://localhost:${port}`}`);
diff --git a/src/cli/exit.ts b/src/cli/exit.ts
index 99e56f97b..2dd3d1374 100644
--- a/src/cli/exit.ts
+++ b/src/cli/exit.ts
@@ -8,6 +8,8 @@
  */
 /* eslint-disable custom-rules/no-process-exit -- centralized CLI exit point */
 
+import { redactForLog } from '../utils/sensitive.js'
+
 // `return undefined as never` (not a post-exit throw) — tests spy on
 // process.exit and let it return. Call sites write `return cliError(...)`
 // where subsequent code would dereference narrowed-away values under mock.
@@ -18,7 +20,7 @@
 /** Write an error message to stderr (if given) and exit with code 1. */
 export function cliError(msg?: string): never {
   // biome-ignore lint/suspicious/noConsole: centralized CLI error output
-  if (msg) console.error(msg)
+  if (msg) console.error(redactForLog(msg))
   process.exit(1)
   return undefined as never
 }
diff --git a/src/cli/handlers/mcp.tsx b/src/cli/handlers/mcp.tsx
index ab543af11..554374824 100644
--- a/src/cli/handlers/mcp.tsx
+++ b/src/cli/handlers/mcp.tsx
@@ -51,6 +51,7 @@ import { isFsInaccessible } from '../../utils/errors.js'
 import { gracefulShutdown } from '../../utils/gracefulShutdown.js'
 import { safeParseJSON } from '../../utils/json.js'
 import { getPlatform } from '../../utils/platform.js'
+import { redactUrl, redactValue } from '../../utils/sensitive.js'
 import { cliError, cliOk } from '../exit.js'
 
 async function checkMcpServerHealth(
@@ -214,13 +215,13 @@ export async function mcpListHandler(): Promise<void> {
       // Intentionally excluding sse-ide servers here since they're internal
       if (server.type === 'sse') {
         // biome-ignore lint/suspicious/noConsole:: intentional console output
-        console.log(`${name}: ${server.url} (SSE) - ${status}`)
+        console.log(`${name}: ${redactUrl(server.url)} (SSE) - ${status}`)
       } else if (server.type === 'http') {
         // biome-ignore lint/suspicious/noConsole:: intentional console output
-        console.log(`${name}: ${server.url} (HTTP) - ${status}`)
+        console.log(`${name}: ${redactUrl(server.url)} (HTTP) - ${status}`)
       } else if (server.type === 'claudeai-proxy') {
         // biome-ignore lint/suspicious/noConsole:: intentional console output
-        console.log(`${name}: ${server.url} - ${status}`)
+        console.log(`${name}: ${redactUrl(server.url)} - ${status}`)
       } else if (!server.type || server.type === 'stdio') {
         const stdioServer = server as { command: string; args: string[]; type?: string }
         const args = Array.isArray(stdioServer.args) ? stdioServer.args : []
@@ -259,13 +260,13 @@ export async function mcpGetHandler(name: string): Promise<void> {
     // biome-ignore lint/suspicious/noConsole:: intentional console output
     console.log(`  Type: sse`)
     // biome-ignore lint/suspicious/noConsole:: intentional console output
-    console.log(`  URL: ${server.url}`)
+    console.log(`  URL: ${redactUrl(server.url)}`)
     if (server.headers) {
       // biome-ignore lint/suspicious/noConsole:: intentional console output
       console.log('  Headers:')
       for (const [key, value] of Object.entries(server.headers)) {
         // biome-ignore lint/suspicious/noConsole:: intentional console output
-        console.log(`    ${key}: ${value}`)
+        console.log(`    ${redactValue(key)}: ${redactValue(key, value)}`)
       }
     }
     if (server.oauth?.clientId || server.oauth?.callbackPort) {
@@ -284,13 +285,13 @@ export async function mcpGetHandler(name: string): Promise<void> {
     // biome-ignore lint/suspicious/noConsole:: intentional console output
     console.log(`  Type: http`)
     // biome-ignore lint/suspicious/noConsole:: intentional console output
-    console.log(`  URL: ${server.url}`)
+    console.log(`  URL: ${redactUrl(server.url)}`)
     if (server.headers) {
       // biome-ignore lint/suspicious/noConsole:: intentional console output
       console.log('  Headers:')
       for (const [key, value] of Object.entries(server.headers)) {
         // biome-ignore lint/suspicious/noConsole:: intentional console output
-        console.log(`    ${key}: ${value}`)
+        console.log(`    ${redactValue(key)}: ${redactValue(key, value)}`)
       }
     }
     if (server.oauth?.clientId || server.oauth?.callbackPort) {
@@ -318,7 +319,7 @@ export async function mcpGetHandler(name: string): Promise<void> {
       console.log('  Environment:')
       for (const [key, value] of Object.entries(server.env)) {
         // biome-ignore lint/suspicious/noConsole:: intentional console output
-        console.log(`    ${key}=${value}`)
+        console.log(`    ${redactValue(key)}=${redactValue(key, value)}`)
       }
     }
   }
diff --git a/src/utils/claudeInChrome/chromeNativeHost.ts b/src/utils/claudeInChrome/chromeNativeHost.ts
index 4052a6064..f3556e422 100644
--- a/src/utils/claudeInChrome/chromeNativeHost.ts
+++ b/src/utils/claudeInChrome/chromeNativeHost.ts
@@ -20,6 +20,7 @@ import { homedir, platform } from 'os'
 import { join } from 'path'
 import { z } from 'zod'
 import { lazySchema } from '../lazySchema.js'
+import { redactForLog } from '../sensitive.js'
 import { jsonParse, jsonStringify } from '../slowOperations.js'
 import { getSecureSocketPath, getSocketDir } from './common.js'
 
@@ -32,17 +33,18 @@ const LOG_FILE =
     : undefined
 
 function log(message: string, ...args: unknown[]): void {
+  const redactedMessage = redactForLog(message)
   if (LOG_FILE) {
     const timestamp = new Date().toISOString()
     const formattedArgs = args.length > 0 ? ' ' + jsonStringify(args) : ''
-    const logLine = `[${timestamp}] [Claude Chrome Native Host] ${message}${formattedArgs}\n`
+    const logLine = `[${timestamp}] [Claude Chrome Native Host] ${redactedMessage}${formattedArgs}\n`
     // Fire-and-forget: logging is best-effort and callers (including event
     // handlers) don't await
     void appendFile(LOG_FILE, logLine).catch(() => {
       // Ignore file write errors
     })
   }
-  console.error(`[Claude Chrome Native Host] ${message}`, ...args)
+  console.error(`[Claude Chrome Native Host] ${redactedMessage}`, ...args)
 }
 /**
  * Send a message to stdout (Chrome native messaging protocol)
diff --git a/src/utils/log.ts b/src/utils/log.ts
index 405afaf4d..dc9c915e3 100644
--- a/src/utils/log.ts
+++ b/src/utils/log.ts
@@ -20,6 +20,7 @@ import { isEnvTruthy } from './envUtils.js'
 import { toError, shortErrorStack } from './errors.js'
 import { isEssentialTrafficOnly } from './privacyLevel.js'
 import { jsonParse } from './slowOperations.js'
+import { redactForLog } from './sensitive.js'
 
 /**
  * Gets the display title for a log/session with fallback logic.
@@ -159,7 +160,10 @@ export function logError(error: unknown): void {
   const err = toError(error)
   if (feature('HARD_FAIL') && isHardFailMode()) {
     // biome-ignore lint/suspicious/noConsole:: intentional crash output
-    console.error('[HARD FAIL] logError called with:', err.stack || err.message)
+    console.error(
+      '[HARD FAIL] logError called with:',
+      redactForLog(err.stack || err.message),
+    )
     // eslint-disable-next-line custom-rules/no-process-exit
     process.exit(1)
   }
diff --git a/src/utils/pipeTransport.ts b/src/utils/pipeTransport.ts
index 3d1974e33..d697e3073 100644
--- a/src/utils/pipeTransport.ts
+++ b/src/utils/pipeTransport.ts
@@ -262,12 +262,13 @@ export class PipeServer extends EventEmitter {
    */
   private async startTcpServer(port: number): Promise<void> {
     return new Promise<void>((resolve, reject) => {
+      const host = process.env.PIPE_HOST || '127.0.0.1'
       this.tcpServer = createServer(socket => this.setupSocket(socket))
       this.tcpServer.on('error', reject)
-      this.tcpServer.listen(port, '0.0.0.0', () => {
+      this.tcpServer.listen(port, host, () => {
         const addr = this.tcpServer!.address()
         if (addr && typeof addr === 'object') {
-          this._tcpAddress = { host: '0.0.0.0', port: addr.port }
+          this._tcpAddress = { host, port: addr.port }
         }
         resolve()
       })
diff --git a/src/utils/sensitive.ts b/src/utils/sensitive.ts
new file mode 100644
index 000000000..137861834
--- /dev/null
+++ b/src/utils/sensitive.ts
@@ -0,0 +1,79 @@
+const REDACTED = '[REDACTED]'
+
+const SENSITIVE_KEY_PATTERN =
+  /(api[_-]?key|auth(?:orization)?|bearer|cookie|credential|password|secret|session|token)/i
+
+const SENSITIVE_QUERY_PARAMS = new Set([
+  'access_token',
+  'api_key',
+  'apikey',
+  'auth',
+  'authorization',
+  'client_secret',
+  'code',
+  'credential',
+  'key',
+  'password',
+  'refresh_token',
+  'secret',
+  'session',
+  'token',
+])
+
+const TOKEN_PATTERNS: Array<[RegExp, string]> = [
+  [/\b(sk-ant-[A-Za-z0-9_-]{10,})\b/g, REDACTED],
+  [/\b(AKIA|ASIA)[A-Z0-9]{16}\b/g, REDACTED],
+  [/\b(ghp|gho|ghs|ghu|github_pat)_[A-Za-z0-9_]{10,}\b/g, REDACTED],
+  [/\bnpm_[A-Za-z0-9]{36}\b/g, REDACTED],
+  [/\bxox[baporst]-[A-Za-z0-9-]{10,}\b/g, REDACTED],
+  [/\bBearer\s+[A-Za-z0-9._~+/-]+=*\b/gi, `Bearer ${REDACTED}`],
+  [/\bBasic\s+[A-Za-z0-9+/]+=*\b/gi, `Basic ${REDACTED}`],
+]
+
+function isSensitiveKey(key: string): boolean {
+  return SENSITIVE_KEY_PATTERN.test(key)
+}
+
+export function redactUrl(urlString: string): string {
+  try {
+    const parsed = new URL(urlString)
+    if (parsed.username) parsed.username = REDACTED
+    if (parsed.password) parsed.password = REDACTED
+
+    for (const key of [...parsed.searchParams.keys()]) {
+      if (SENSITIVE_QUERY_PARAMS.has(key.toLowerCase())) {
+        parsed.searchParams.set(key, REDACTED)
+      }
+    }
+
+    return redactForLog(parsed.toString())
+  } catch {
+    return redactForLog(urlString)
+  }
+}
+
+export function redactValue(key: string, value: unknown): string
+export function redactValue(value: unknown): string
+export function redactValue(keyOrValue: unknown, value?: unknown): string {
+  if (arguments.length > 1) {
+    const key = String(keyOrValue)
+    return isSensitiveKey(key) ? REDACTED : redactForLog(String(value ?? ''))
+  }
+
+  return redactForLog(String(keyOrValue ?? ''))
+}
+
+export function redactForLog(message: unknown): string {
+  let redacted = String(message ?? '')
+
+  for (const [pattern, replacement] of TOKEN_PATTERNS) {
+    redacted = redacted.replace(pattern, replacement)
+  }
+
+  redacted = redacted.replace(
+    /\b([A-Za-z0-9_.-]*(?:api[_-]?key|auth|authorization|bearer|cookie|credential|password|secret|session|token)[A-Za-z0-9_.-]*)\s*[:=]\s*("[^"]+"|'[^']+'|[^\s,;]+)/gi,
+    (_match, key: string) => `${key}=${REDACTED}`,
+  )
+
+  return redacted
+}