Category

Browser Extension

Security vulnerabilities and automated fixes for browser extension issues

8 posts found

critical8 min

How Server-Side Request Forgery happens in Browser Extensions and how to fix it

A Server-Side Request Forgery (SSRF) vulnerability in `offscreen.js` allowed attackers to supply malicious feed URLs that the browser extension would fetch without validation, potentially exposing internal network services including cloud metadata endpoints. The fix introduces a dedicated `validateFeedUrl` utility and disables automatic redirect following, closing the attack vector before requests leave the extension. This kind of vulnerability is especially dangerous in browser extensions becau

#ssrf#javascript#browser-extension+3 more
A
anupamme
Aug 26, 2026
critical9 min

How Cross-Site Scripting (XSS) happens in JavaScript browser extensions and how to fix it

A cross-site scripting (XSS) vulnerability was discovered in `extension/lib/chatgpt.js` where the `chatgpt.alert()` function used `modalMsg.innerText` to set user-controlled content before passing it to `chatgpt.renderHTML()`, allowing injected HTML to be rendered unsanitized. The fix replaces `innerText` with `textContent` and introduces an allowlist of safe HTML tags and attributes inside `renderHTML()`. This prevents attackers from injecting arbitrary HTML or JavaScript through modal message

#xss#javascript#browser-extension+2 more
A
anupamme
Aug 26, 2026
high7 min

How XSS via Incomplete HTML Escaping happens in JavaScript Browser Extensions and how to fix it

A high-severity cross-site scripting (XSS) vulnerability was discovered in `extension/lib/popup-response.js`, where the `esc()` HTML-escaping function failed to encode backtick characters. Because backticks are valid JavaScript template literal delimiters and can serve as event handler injection vectors in older browsers, this gap allowed attacker-controlled data to break out of safe HTML encoding and potentially execute arbitrary scripts. The fix adds a single `.replace(/\`/g, "`")` call to

#xss#javascript#browser-extension+3 more
A
anupamme
Aug 26, 2026
critical9 min

How Unsafe eval() in Browser Chrome Context Happens in JavaScript and How to Fix It

A critical code injection vulnerability in `command-palette/dynamic-commands.js` allowed arbitrary JavaScript to execute in the browser's privileged chrome context by passing unsanitized code from a user-controlled settings file directly into `Cu.evalInSandbox()`. The fix introduces an HMAC-based trust system that cryptographically hashes each custom command's code and requires explicit user approval before execution. This prevents attackers who can write to the settings file from silently injec

#injection#javascript#browser-extension+4 more
A
anupamme
Aug 26, 2026
critical6 min

How innerHTML XSS happens in JavaScript browser extensions and how to fix it

A cross-site scripting (XSS) vulnerability in `sidepanel/panel.js` allowed injected `<script>` tags and inline event handlers to execute inside a privileged browser extension context. The `renderChat` function passed markdown-rendered assistant content directly to `row.innerHTML` without stripping dangerous HTML patterns. The fix applies targeted regex sanitization to remove script blocks and `on*` event handler attributes before the content reaches the DOM.

#xss#javascript#browser-extension+2 more
A
anupamme
Aug 26, 2026
critical8 min

How Command Injection happens in Python subprocess calls and how to fix it

A critical command injection vulnerability in `host/beectl-py2.py` allowed attackers to pass arbitrary subprocess arguments through a browser extension's JSON configuration, enabling execution of malicious shell commands on the host machine. The fix introduces two new validation functions — `sanitize_args()` and `sanitize_ext()` — that enforce strict type and content constraints on user-controlled input before it reaches the `subprocess` call. This change closes a direct path from browser extens

#command-injection#python#subprocess+2 more
A
anupamme
Aug 26, 2026
critical7 min

How Insecure API Key Transmission Happens in JavaScript Browser Extensions and How to Fix It

A critical vulnerability in `utils/common.js` allowed API keys to be transmitted over unencrypted HTTP connections to remote servers, exposing them to network interception. The `buildModelApiRequest` function at line 490 constructed API requests without validating the transport protocol, enabling man-in-the-middle attacks. The fix enforces HTTPS for all remote API endpoints while preserving HTTP access for local development servers on loopback addresses.

#security#javascript#api-keys+4 more
A
anupamme
Aug 5, 2026
medium5 min

Wildcard PostMessage Leak: How One Character Exposed User Sessions

A critical security flaw in a browser extension's authentication flow was sending sensitive session tokens and user data to any website using the wildcard "*" origin in postMessage. This vulnerability could have allowed malicious sites to intercept authentication credentials, but was fixed by restricting message delivery to the application's own origin.

#security#postmessage#browser-extension+4 more
O
orbisai0security
Mar 6, 2026