Vulnerability · Published Feb 9, 2026 · Assigned by GitHub_M

CVE-2026-25480FileStore key canonicalization collisions allow response cache mixup/poisoning (ASCII ord + Unicode NFKD)

Medium 6.5

In plain English

A medium-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 0.5% (higher than 40% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium

Exploit odds (30 days)0.5%top 59.9% 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, FileStore maps cache keys to filenames using Unicode NFKD normalization and ord() substitution without separators, creating key collisions. When FileStore is used as response-cache backend, an unauthenticated remote attacker can trigger cache key collisions via crafted paths, causing one URL to serve cached responses of another (cache poisoning/mixup). This vulnerability is fixed in 2.20.0.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
PyPI	litestar	2.20.0	GHSA-vxqx-rh46-q2pg
PyPI	litestar	2.20.0	PYSEC-2026-2197

Affected products (as reported)

Vendor	Product	Versions
litestar-org	litestar	< 2.20.0

Weakness: CWE-176 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

References

https://github.com/litestar-org/litestar/security/advisories/GHSA-vxqx-rh46-q2pg x_refsource_CONFIRM
https://github.com/litestar-org/litestar/commit/85db6183a76f8a6b3fd6ee3c88d860b9f37a2cca 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