Disclosure summary
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.
Source-specific records & product guidance
Sources retain their own attribution and scoring. Follow the original record to confirm affected versions, fixed releases, and configuration conditions.
GitHub Reviewed Security Advisories · GHSA-3qf3-8w2g-rqmx
Open original source · Updated Oct 05, 2026
python-jose algorithm confusion guard bypassed by DER-encoded public keys
Source severity: CRITICAL / 9.3
| Ecosystem | Package | Affected range | First patched |
|---|---|---|---|
| pip | python-jose | Not supplied |
Original records & references
- NIST NVD record
- CVE Program record
- github.com — Reviewed advisory
PUBLISHED 2026-09-03T17:31:15-04:00
MODIFIED 2026-10-05T18:55:02-04:00
INGESTED 2026-10-06T11:45:33-04:00