GHSA-869j-r97x-hx2g

## Summary

Anki launches a local HTTP server to serve media files and web pages for parts of its interface. The server fails to validate requests in the following ways: 1. No sufficient validation of the Origin header. 2. Some endpoints are vulnerable to path traversal attacks.

This allows malicious websites to exfiltrate local files given a known path.

## Browser impact

The severity varies by browser because of Private Network Access (PNA), a newer spec that restricts web pages from making requests to localhost/local network addresses:

Chrome/Chromium (including Edge, Brave): Largely protected, as Chrome has implemented PNA restrictions for several years and now puts local network access behind a permission prompt. Safari: Hasn't implemented PNA yet, though macOS has some OS-level protections. Firefox: Most vulnerable — hasn't implemented PNA yet, though it's reportedly planned for Firefox 151.

## Patches

The issue was fixed as of Anki 25.09.3