Anki's local HTTP server does not sufficiently validate requests
## Summary Anki launches a local HTTP server to serve media files and web pages for parts of its interface. While the server has a CORS setup, requests from other origins were not blocked, allowing malicious websites to potentially trigger side-effecting requests. ## 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 ### References https://x.com/taviso/status/2051310678800253318
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2026-59153US | — | — | ||
Anki is a program for creating and reviewing flashcards. Prior to 25.09.3, Anki launches a local HTTP server to serve media files and web pages for parts of its interface, but requ… | ||||
references
External citations — patches, advisories, analysis.
- https://github.com/ankitects/ankiPACKAGE
- https://github.com/ankitects/anki/commit/858e5689d0e4fd24f74856c7e8f245412694a219WEB
- https://github.com/ankitects/anki/releases/tag/25.09.3WEB
- https://github.com/ankitects/anki/security/advisories/GHSA-869j-r97x-hx2gWEB
- https://nvd.nist.gov/vuln/detail/CVE-2026-59153ADVISORY
- https://x.com/taviso/status/2051310678800253318WEB
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