CVE-2026-85394

python-jose through version 3.5.0 contains an algorithm confusion vulnerability in its HMAC key validation logic. The library fails to properly reject DER-encoded public keys that lack PEM armor or SSH prefixes, allowing them to be accepted as HMAC secrets. An attacker who possesses the service's...

CVE-2026-85394 python-jose through 3.5.0 Algorithm Confusion via DER-encoded Public Key as HMAC Secret

python-jose through 3.5.0 fails to properly validate asymmetric keys in HMAC initialization, accepting DER-encoded public keys that lack PEM armor or SSH prefixes. Attackers holding the service's public key can forge HS256 tokens that pass verification when algorithms are not explicitly restricte...