CVSS 4.0
9.3 criticalCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:NCVE-2026-85394
Critical (9.3). EPSS 0.2% chance of exploitation in the next 30 days. Fixed in python-jose 3.4.0.
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.
Severity
CVSS 3.1
9.1 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N- EPSS
- 0.2% chance of exploitation in the next 30 days; higher than 12% of CVEs (scores of 2026-10-31)
- CWE
- CWE-347
- Published
- Modified
- Record from
- the NVD, synced
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-3qf3-8w2g-rqmx | PyPI | python-jose | <=3.5.0 | no fix published |
| GHSA-6c5p-j8vq-pqhj | PyPI | python-jose | <3.4.0 | 3.4.0 |
| PYSEC-2024-232 | PyPI | python-jose | <3.4.0 | 3.4.0 |
| PYSEC-2026-4298 | PyPI | python-jose | <=3.5.0 | no fix published |
References
- https://github.com/advisories/GHSA-6c5p-j8vq-pqhj
- https://github.com/mpdavis/python-jose
- https://github.com/mpdavis/python-jose/blob/018b310ddb8b50dcfd09a0c152117835a21dd656/jose/backends/native.py
- https://github.com/mpdavis/python-jose/blob/018b310ddb8b50dcfd09a0c152117835a21dd656/jose/utils.py
- https://github.com/mpdavis/python-jose/issues/414