Vulnerability · Published Feb 9, 2026 · Assigned by GitHub_M

CVE-2026-25478Litestar has a CORS origin allowlist bypass due to unescaped regex metacharacters in allowed origins

High 7.4

In plain English

A high-severity security flaw in litestar from litestar-org. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 38% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.4High

Exploit odds (30 days)0.4%top 61.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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 packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
PyPI	litestar	2.20.0	GHSA-2p2x-hpg8-cqp2
PyPI	litestar	2.20.0	PYSEC-2026-2195

Affected products (as reported)

Vendor	Product	Versions
litestar-org	litestar	< 2.20.0

Weakness: CWE-942 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N

References

https://github.com/litestar-org/litestar/security/advisories/GHSA-2p2x-hpg8-cqp2 x_refsource_CONFIRM
https://github.com/litestar-org/litestar/commit/eb87703b309efcc0d1b087dcb12784e76b003d5a x_refsource_MISC
https://docs.litestar.dev/2/release-notes/changelog.html#2.20.0 x_refsource_MISC
https://github.com/litestar-org/litestar/releases/tag/v2.20.0 x_refsource_MISC