diff --git a/VIBE/CHAT_LOG.md b/VIBE/CHAT_LOG.md
index 7221178..0d9ca70 100644
--- a/VIBE/CHAT_LOG.md
+++ b/VIBE/CHAT_LOG.md
@@ -1,5 +1,11 @@
 # Chat Log
 
+### User
+Implement SA-006 permission changes: remove `<all_urls>` and unnecessary `tabs`, request exact access to the configured self-hosted backend, and keep page capture behind `activeTab`.
+
+### Assistant outcome
+Updated the Firefox extension manifest to use `activeTab` and `storage` only, with Firefox-compatible optional HTTP/HTTPS host permissions. The options login page now normalizes the backend to an origin and requests only that origin during the user-initiated login. The popup checks that exact grant before session validation or link submission, so it does not perform backend calls without permission.
+
 ## 2026-08-24
 
 ### User
diff --git a/VIBE/PROMPTS.md b/VIBE/PROMPTS.md
index b98e905..3aa52a0 100644
--- a/VIBE/PROMPTS.md
+++ b/VIBE/PROMPTS.md
@@ -181,6 +181,7 @@
 161. The popup still shows the sign-in block even though the authenticated session text is displayed; show the block only when signed out.
 162. The authenticated session text and sign-in block are still shown together.
 163. Use the VIBE directory to log interactions.
+164. Implement SA-006: remove broad Firefox extension host access and unnecessary tabs permission, request exact configured backend origin access, and keep page capture behind activeTab.
 
 ## Future entries
 
diff --git a/XPI/unsigned/LinkLog-0.1.0.xpi b/XPI/unsigned/LinkLog-0.1.0.xpi
index 648866e..69c179e 100644
Binary files a/XPI/unsigned/LinkLog-0.1.0.xpi and b/XPI/unsigned/LinkLog-0.1.0.xpi differ
diff --git a/webextension/manifest.json b/webextension/manifest.json
index e2d42b5..3e9f104 100644
--- a/webextension/manifest.json
+++ b/webextension/manifest.json
@@ -6,11 +6,11 @@
   "default_locale": "en-US",
   "permissions": [
     "activeTab",
-    "storage",
-    "tabs"
+    "storage"
   ],
-  "host_permissions": [
-    "<all_urls>"
+  "optional_permissions": [
+    "http://*/*",
+    "https://*/*"
   ],
   "action": {
     "default_title": "__MSG_extensionName__",
diff --git a/webextension/options.js b/webextension/options.js
index 12480df..0948442 100644
--- a/webextension/options.js
+++ b/webextension/options.js
@@ -13,6 +13,34 @@ const signOutButton = document.getElementById('sign-out');
 
 const t = window.linklogI18n;
 
+function normalizeBackendOrigin(backendUrl) {
+  try {
+    const url = new URL(backendUrl);
+    if (!['http:', 'https:'].includes(url.protocol)) {
+      return null;
+    }
+    return url.origin;
+  } catch (error) {
+    return null;
+  }
+}
+
+async function hasBackendPermission(backendUrl) {
+  const origin = normalizeBackendOrigin(backendUrl);
+  if (!origin) return false;
+  return browser.permissions.contains({origins: [`${origin}/*`]});
+}
+
+async function requestBackendPermission(backendUrl) {
+  const origin = normalizeBackendOrigin(backendUrl);
+  if (!origin) return false;
+  try {
+    return await browser.permissions.request({origins: [`${origin}/*`]});
+  } catch (error) {
+    return false;
+  }
+}
+
 function setStatus(message, isError = false) {
   statusEl.textContent = message;
   statusEl.classList.remove('hidden');
@@ -25,7 +53,7 @@ async function loadSettings() {
   backendUrlInput.value = settings.backendUrl || '';
   emailInput.value = settings.email || '';
 
-  if (settings.accessToken && settings.backendUrl) {
+  if (settings.accessToken && settings.backendUrl && await hasBackendPermission(settings.backendUrl)) {
     try {
       const response = await fetch(
         `${settings.backendUrl}/api/auth/me`,
@@ -61,7 +89,7 @@ async function clearSession() {
 
 async function saveSettingsAndLogin(event) {
   event.preventDefault();
-  const backendUrl = backendUrlInput.value.trim();
+  const backendUrl = normalizeBackendOrigin(backendUrlInput.value.trim());
   const email = emailInput.value.trim();
   const password = passwordInput.value;
   const otp = otpInput.value.trim();
@@ -71,6 +99,11 @@ async function saveSettingsAndLogin(event) {
     return;
   }
 
+  if (!(await requestBackendPermission(backendUrl))) {
+    setStatus(t('unableToLogIn'), true);
+    return;
+  }
+
   try {
     const response = await fetch(`${backendUrl}/api/auth/login`, {
       method: 'POST',
@@ -104,8 +137,9 @@ async function saveSettingsAndLogin(event) {
 
 async function signOut() {
   const settings = await browser.storage.local.get(['accessToken']);
-  if (settings.accessToken) {
-    await fetch(`${backendUrlInput.value.trim()}/api/auth/logout`, {
+  const backendUrl = normalizeBackendOrigin(backendUrlInput.value.trim());
+  if (settings.accessToken && await hasBackendPermission(backendUrl)) {
+    await fetch(`${backendUrl}/api/auth/logout`, {
       method: 'POST',
       headers: { 'Content-Type': 'application/json' },
       body: JSON.stringify({ token: settings.accessToken }),
diff --git a/webextension/popup.js b/webextension/popup.js
index 3a538a4..97761ac 100644
--- a/webextension/popup.js
+++ b/webextension/popup.js
@@ -16,6 +16,24 @@ const authSession = document.getElementById('auth-session');
 
 const t = window.linklogI18n;
 
+function normalizeBackendOrigin(backendUrl) {
+  try {
+    const url = new URL(backendUrl);
+    if (!['http:', 'https:'].includes(url.protocol)) {
+      return null;
+    }
+    return url.origin;
+  } catch (error) {
+    return null;
+  }
+}
+
+async function hasBackendPermission(backendUrl) {
+  const origin = normalizeBackendOrigin(backendUrl);
+  if (!origin) return false;
+  return browser.permissions.contains({origins: [`${origin}/*`]});
+}
+
 function setStatus(message, isError = false) {
   statusEl.textContent = message;
   statusEl.classList.remove('hidden');
@@ -33,7 +51,7 @@ async function getSettings() {
 }
 
 async function validateSession(settings) {
-  if (!settings.backendUrl || !settings.accessToken) return null;
+  if (!settings.backendUrl || !settings.accessToken || !(await hasBackendPermission(settings.backendUrl))) return null;
   try {
     const response = await fetch(`${settings.backendUrl}/api/auth/me`, {
       headers: {'Authorization': `Bearer ${settings.accessToken}`},
@@ -157,7 +175,7 @@ async function populateCurrentTab() {
 
 async function checkExistingLink() {
   const settings = await getSettings();
-  if (!settings.backendUrl || !settings.accessToken || !titleInput.value || !urlInput.value) return;
+  if (!settings.backendUrl || !settings.accessToken || !(await hasBackendPermission(settings.backendUrl)) || !titleInput.value || !urlInput.value) return;
   try {
     const response = await fetch(`${settings.backendUrl}/api/links/check?${new URLSearchParams({
       title: titleInput.value,
@@ -181,7 +199,7 @@ async function handleSubmit(event) {
   const token = settings.accessToken;
   const backendUrl = settings.backendUrl;
 
-  if (!token || !backendUrl) {
+  if (!token || !backendUrl || !(await hasBackendPermission(backendUrl))) {
     setStatus(t('configureAndLogIn'), true);
     browser.runtime.openOptionsPage();
     return;