CVE-2026-25478

HIGH7.4

Litestar has a CORS origin allowlist bypass due to unescaped regex metacharacters in allowed origins

Published Feb 9, 2026

Modified 3 weeks ago

Details

Litestar is an Asynchronous Server Gateway Interface (ASGI) framework. Prior to 2.20.0, CORSConfig.allowed_origins_regex is constructed using a regex built from configured allowlist values and used with fullmatch() for validation. Because metacharacters are not escaped, a malicious origin can match unexpectedly. The check relies on allowed_origins_regex.fullmatch(origin). This vulnerability is fixed in 2.20.0.

References

WEB

https://docs.litestar.dev/2/release-notes/changelog.html#2.20.0

WEB

https://github.com/litestar-org/litestar/commit/eb87703b309efcc0d1b087dcb12784e76b003d5a

WEB

https://github.com/litestar-org/litestar/releases/tag/v2.20.0

WEB

https://github.com/litestar-org/litestar/security/advisories/GHSA-2p2x-hpg8-cqp2

ADVISORY

https://www.cve.org/CVERecord?id=CVE-2026-25478

CVSS Analysis