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Medium · 6.5 CVE-2026-25480 EUVD-2026-6498GHSA-vxqx-rh46-q2pgPYSEC-2026-2197

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

Published Feb 9, 2026 · Updated Feb 10, 2026 · Assigned by GitHub_M

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 products

VendorProductAffectedFixed
litestar-org litestar < 2.20.0 —

Affected packages

EcosystemPackageAffectedFixedRecord
PyPI litestar >= 2.19.0, < 2.20.0 2.20.0 GHSA-vxqx-rh46-q2pg
PyPI litestar < 2.20.0 2.20.0 PYSEC-2026-2197

References