diff --git a/browse/src/browser-manager.ts b/browse/src/browser-manager.ts
index a6eda991b..4784c5431 100644
--- a/browse/src/browser-manager.ts
+++ b/browse/src/browser-manager.ts
@@ -57,6 +57,9 @@ export class BrowserManager {
   private dialogAutoAccept: boolean = true;
   private dialogPromptText: string | null = null;
 
+  // ─── Cookie Origin Tracking ────────────────────────────────
+  private cookieImportedDomains: Set<string> = new Set();
+
   // ─── Handoff State ─────────────────────────────────────────
   private isHeaded: boolean = false;
   private consecutiveFailures: number = 0;
@@ -521,6 +524,19 @@ export class BrowserManager {
     return this.dialogPromptText;
   }
 
+  // ─── Cookie Origin Tracking ────────────────────────────────
+  trackCookieImportDomains(domains: string[]): void {
+    for (const d of domains) this.cookieImportedDomains.add(d);
+  }
+
+  getCookieImportedDomains(): ReadonlySet<string> {
+    return this.cookieImportedDomains;
+  }
+
+  hasCookieImports(): boolean {
+    return this.cookieImportedDomains.size > 0;
+  }
+
   // ─── Viewport ──────────────────────────────────────────────
   async setViewport(width: number, height: number) {
     await this.getPage().setViewportSize({ width, height });
diff --git a/browse/src/read-commands.ts b/browse/src/read-commands.ts
index 5615b60f0..9da3cee1f 100644
--- a/browse/src/read-commands.ts
+++ b/browse/src/read-commands.ts
@@ -86,6 +86,38 @@ export async function getCleanText(page: Page | Frame): Promise<string> {
   });
 }
 
+/**
+ * When cookies have been imported for specific domains, block JS execution
+ * on pages whose origin doesn't match any imported cookie domain.
+ * Prevents cross-origin cookie exfiltration via `js document.cookie` or
+ * similar when the agent navigates to an untrusted page.
+ */
+function assertJsOriginAllowed(bm: BrowserManager, pageUrl: string): void {
+  if (!bm.hasCookieImports()) return;
+
+  let hostname: string;
+  try {
+    hostname = new URL(pageUrl).hostname;
+  } catch {
+    return; // about:blank, data: URIs — allow (no cookies at risk)
+  }
+
+  const importedDomains = bm.getCookieImportedDomains();
+  const allowed = [...importedDomains].some(domain => {
+    // Exact match or subdomain match (e.g., ".github.com" matches "api.github.com")
+    const normalized = domain.startsWith('.') ? domain : '.' + domain;
+    return hostname === domain.replace(/^\./, '') || hostname.endsWith(normalized);
+  });
+
+  if (!allowed) {
+    throw new Error(
+      `JS execution blocked: current page (${hostname}) does not match any cookie-imported domain. ` +
+      `Imported cookies for: ${[...importedDomains].join(', ')}. ` +
+      `This prevents cross-origin cookie exfiltration. Navigate to an imported domain or run without imported cookies.`
+    );
+  }
+}
+
 export async function handleReadCommand(
   command: string,
   args: string[],
@@ -166,6 +198,7 @@ export async function handleReadCommand(
     case 'js': {
       const expr = args[0];
       if (!expr) throw new Error('Usage: browse js <expression>');
+      assertJsOriginAllowed(bm, page.url());
       const wrapped = wrapForEvaluate(expr);
       const result = await target.evaluate(wrapped);
       return typeof result === 'object' ? JSON.stringify(result, null, 2) : String(result ?? '');
@@ -174,6 +207,7 @@ export async function handleReadCommand(
     case 'eval': {
       const filePath = args[0];
       if (!filePath) throw new Error('Usage: browse eval <js-file>');
+      assertJsOriginAllowed(bm, page.url());
       validateReadPath(filePath);
       if (!fs.existsSync(filePath)) throw new Error(`File not found: ${filePath}`);
       const code = fs.readFileSync(filePath, 'utf-8');
diff --git a/browse/src/write-commands.ts b/browse/src/write-commands.ts
index 02413daf8..3194eb487 100644
--- a/browse/src/write-commands.ts
+++ b/browse/src/write-commands.ts
@@ -314,32 +314,58 @@ export async function handleWriteCommand(
       }
 
       await page.context().addCookies(cookies);
+      const importedDomains = [...new Set(cookies.map((c: any) => c.domain).filter(Boolean))];
+      if (importedDomains.length > 0) bm.trackCookieImportDomains(importedDomains);
       return `Loaded ${cookies.length} cookies from ${filePath}`;
     }
 
     case 'cookie-import-browser': {
       // Two modes:
       // 1. Direct CLI import: cookie-import-browser <browser> --domain <domain> [--profile <profile>]
-      // 2. Open picker UI: cookie-import-browser [browser]
+      //    Requires --domain (or --all to explicitly import everything).
+      // 2. Open picker UI: cookie-import-browser [browser] (interactive domain selection)
       const browserArg = args[0];
       const domainIdx = args.indexOf('--domain');
       const profileIdx = args.indexOf('--profile');
+      const hasAll = args.includes('--all');
       const profile = (profileIdx !== -1 && profileIdx + 1 < args.length) ? args[profileIdx + 1] : 'Default';
 
       if (domainIdx !== -1 && domainIdx + 1 < args.length) {
-        // Direct import mode — no UI
+        // Direct import mode — scoped to specific domain
         const domain = args[domainIdx + 1];
         const browser = browserArg || 'comet';
         const result = await importCookies(browser, [domain], profile);
         if (result.cookies.length > 0) {
           await page.context().addCookies(result.cookies);
+          bm.trackCookieImportDomains([domain]);
         }
         const msg = [`Imported ${result.count} cookies for ${domain} from ${browser}`];
         if (result.failed > 0) msg.push(`(${result.failed} failed to decrypt)`);
         return msg.join(' ');
       }
 
-      // Picker UI mode — open in user's browser
+      if (hasAll) {
+        // Explicit all-cookies import — requires --all flag as a deliberate opt-in.
+        // Imports every non-expired cookie domain from the browser.
+        const browser = browserArg || 'comet';
+        const { listDomains } = await import('./cookie-import-browser');
+        const { domains } = listDomains(browser, profile);
+        const allDomainNames = domains.map(d => d.domain);
+        if (allDomainNames.length === 0) {
+          return `No cookies found in ${browser} (profile: ${profile})`;
+        }
+        const result = await importCookies(browser, allDomainNames, profile);
+        if (result.cookies.length > 0) {
+          await page.context().addCookies(result.cookies);
+          bm.trackCookieImportDomains(allDomainNames);
+        }
+        const msg = [`Imported ${result.count} cookies across ${Object.keys(result.domainCounts).length} domains from ${browser}`];
+        msg.push('(used --all: all browser cookies imported — consider --domain for tighter scoping)');
+        if (result.failed > 0) msg.push(`(${result.failed} failed to decrypt)`);
+        return msg.join(' ');
+      }
+
+      // Picker UI mode — open in user's browser for interactive domain selection
       const port = bm.serverPort;
       if (!port) throw new Error('Server port not available');
 
@@ -355,7 +381,7 @@ export async function handleWriteCommand(
         // open may fail silently — URL is in the message below
       }
 
-      return `Cookie picker opened at ${pickerUrl}\nDetected browsers: ${browsers.map(b => b.name).join(', ')}\nSelect domains to import, then close the picker when done.`;
+      return `Cookie picker opened at ${pickerUrl}\nDetected browsers: ${browsers.map(b => b.name).join(', ')}\nSelect domains to import, then close the picker when done.\n\nTip: For scripted imports, use --domain <domain> to scope cookies to a single domain.`;
     }
 
     default: