CVE-2026-25478

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

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.

Affected

litestar-org · litestar

CVSS v3.1 NVD

6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

CVSS v3.1 GITHUB

7.4 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N

EPSS

0.54% chance of exploitation in the next 30 days, 44th percentile

Published

2026-02-09

Updated

2026-02-10

Proof-of-concept exploits (1)

• advisories/GHSA-2p2x-hpg8-cqp2

Security advisories

• litestar-org/litestar/security/advisories/GHSA-2p2x-hpg8-cqp2
• litestar-org/litestar/commit/eb87703b309efcc0d1b087dcb12784e76b003d5a
• https://docs.litestar.dev/2/release-notes/changelog.html#2.20.0

References

• CVE Record
• NVD entry