critical9.1
CVE-2026-85394
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 prefi…
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | python-jose | <= 3.5.0 | none recorded |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-3qf3-8w2g-rqmx
- https://nvd.nist.gov/vuln/detail/CVE-2026-85394
- https://github.com/mpdavis/python-jose/issues/414
- https://github.com/advisories/GHSA-6c5p-j8vq-pqhj
- https://github.com/mpdavis/python-jose/blob/018b310ddb8b50dcfd09a0c152117835a21dd656/jose/backends/native.py
- https://github.com/mpdavis/python-jose/blob/018b310ddb8b50dcfd09a0c152117835a21dd656/jose/utils.py
- https://www.vulncheck.com/advisories/python-jose-through-3.5.0-algorithm-confusion-via-der-encoded-public-key-as-hmac-secret
- https://github.com/mpdavis/python-jose