Vulnerability Description
Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to version 1.6.9, a cryptographic padding oracle vulnerability was identified in the Authlib Python library concerning the implementation of the JSON Web Encryption (JWE) RSA1_5 key management algorithm. Authlib registers RSA1_5 in its default algorithm registry without requiring explicit opt-in, and actively destroys the constant-time Bleichenbacher mitigation that the underlying cryptography library implements correctly. This issue has been patched in version 1.6.9.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Authlib | Authlib | < 1.6.9 |
Related Weaknesses (CWE)
References
- https://github.com/authlib/authlib/commit/48b345f29f6c459f11c6a40162b6c0b742ef2ePatch
- https://github.com/authlib/authlib/releases/tag/v1.6.9ProductRelease Notes
- https://github.com/authlib/authlib/security/advisories/GHSA-7432-952r-cw78ExploitMitigationVendor Advisory
FAQ
What is CVE-2026-28490?
CVE-2026-28490 is a vulnerability with a CVSS score of 6.5 (MEDIUM). Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to version 1.6.9, a cryptographic padding oracle vulnerability was identified in the Authlib Python library concerning ...
How severe is CVE-2026-28490?
CVE-2026-28490 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-28490?
Check the references section above for vendor advisories and patch information. Affected products include: Authlib Authlib.