Medium severity · published Feb 9, 2026
CVE-2026-25478
Litestar has a CORS origin allowlist bypass due to unescaped regex metacharacters in allowed origins
6.5
CVSS
0.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
High
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 39% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
litestar · litestar-org
< 2.20.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-25478
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-25478
Release Notes
https://docs.litestar.dev/2/release-notes/changelog.html#2.20.0
Patch
https://github.com/litestar-org/litestar/commit/eb87703b309efcc0d1b087dcb12784e76b003d5a
Release Notes
https://github.com/litestar-org/litestar/releases/tag/v2.20.0
Exploit
https://github.com/litestar-org/litestar/security/advisories/GHSA-2p2x-hpg8-cqp2
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