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

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 remo...

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

Summary 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 UR...