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 restricted. This is an incomplete fix for CVE-2024-33663.

Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-cjwg-qfpm-7377. This link is maintained to preserve external references.

Original Description

In python-jose 3.3.0 (specifically jwe.decrypt), a vulnerability allows an attacker to cause a Denial-of-Service (DoS) condition by crafting a malicious JSON Web Encryption (JWE) token with an exceptionally high compression ratio. When this token is processed by the server, it results in significant memory allocation and processing time during decompression.