python-jose through 3.5.0 Algorithm Confusion via DER-encoded Public Key as HMAC Secret (mpdavis python-jose)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.22 % · percentile 13 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- VulnCheck
- NVD status
- Deferred
Description
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.
Weaknesses (CWE)
- CWE-347 — Improper Verification of Cryptographic Signature
References
- https://github.com/mpdavis/python-jose/issues/414
- 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/advisories/GHSA-6c5p-j8vq-pqhj
- https://www.vulncheck.com/advisories/python-jose-through-3.5.0-algorithm-confusion-via-der-encoded-public-key-as-hmac-secret
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 4.0 | CRITICAL 9.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N | VulnCheck |
| CVSS 3.1 | CRITICAL 9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N | VulnCheck |
| CVSS 4.0 | CRITICAL 9.3 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD · disclosure@vulncheck.com (Secondary) |
| CVSS 3.1 | CRITICAL 9.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N | NVD · disclosure@vulncheck.com (Secondary) |
Advisories
- GHSA-3qf3-8w2g-rqmx — python-jose algorithm confusion guard bypassed by DER-encoded public keys
- GHSA-6c5p-j8vq-pqhj — python-jose algorithm confusion with OpenSSH ECDSA keys
- PYSEC-2024-232 — python-jose through 3.3.0 has algorithm confusion with OpenSSH ECDSA keys and other key formats. This is similar to CVE-2022-29217.
- PYSEC-2026-4298 — python-jose algorithm confusion guard bypassed by DER-encoded public keys
European references
- ENISA EUVD · EUVD-2026-70671
- GCVE · GCVE-0-2026-85394
CERT-FR advisories
- CERTFR-2026-AVI-1433 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
Affected products
| Product | Versions |
|---|---|
| mpdavis · python-jose | affected 0 ≤ 3.5.0 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |