PYSEC-2026-4298
See a problem?- Import Source
- https://github.com/pypa/advisory-database/blob/main/vulns/python-jose/PYSEC-2026-4298.yaml
- JSON Data
- https://api.osv.dev/v1/vulns/PYSEC-2026-4298
- Aliases
- Published
- 2026-10-15T10:22:43Z
- Modified
- 2026-10-15T14:56:01Z
- Severity
-
- 9.1 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N CVSS Calculator
- 9.3 (Critical) CVSS_V4 - 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 CVSS Calculator
- Summary
- python-jose algorithm confusion guard bypassed by DER-encoded public keys
- Details
-
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.
- References
-
- 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
- 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://pypi.org/project/python-jose
- https://github.com/advisories/GHSA-3qf3-8w2g-rqmx
Affected packages
PyPI / python-jose
Package
- Name
- python-jose
- View open source insights on deps.dev
- Purl
- pkg:pypi/python-jose
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0 Unknown introduced version / All previous versions are affectedLast Affected3.5.0