Vulnerability Description
Authlib is a Python library which builds OAuth and OpenID Connect servers. From version 1.6.5 to before version 1.6.7, previous tests involving passing a malicious JWT containing alg: none and an empty signature was passing the signature verification step without any changes to the application code when a failure was expected.. This issue has been patched in version 1.6.7.
CVSS Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Authlib | Authlib | >= 1.6.5, < 1.6.7 |
Related Weaknesses (CWE)
References
- https://github.com/authlib/authlib/commit/a61c2acb807496e67f32051b5f1b1d5ccf8f0aPatch
- https://github.com/authlib/authlib/commit/b87c32ed07b8ae7f805873e1c9cafd1016761dPatch
- https://github.com/authlib/authlib/security/advisories/GHSA-7wc2-qxgw-g8ggExploitVendor Advisory
- https://access.redhat.com/errata/RHSA-2026:19375
- https://access.redhat.com/errata/RHSA-2026:4942
- https://access.redhat.com/errata/RHSA-2026:5168
- https://access.redhat.com/errata/RHSA-2026:5665
- https://access.redhat.com/errata/RHSA-2026:6309
- https://access.redhat.com/errata/RHSA-2026:6568
- https://access.redhat.com/security/cve/CVE-2026-28802
- https://bugzilla.redhat.com/show_bug.cgi?id=2445120
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-28802.json
FAQ
What is CVE-2026-28802?
CVE-2026-28802 is a vulnerability with a CVSS score of 9.8 (CRITICAL). Authlib is a Python library which builds OAuth and OpenID Connect servers. From version 1.6.5 to before version 1.6.7, previous tests involving passing a malicious JWT containing alg: none and an empt...
How severe is CVE-2026-28802?
CVE-2026-28802 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-28802?
Check the references section above for vendor advisories and patch information. Affected products include: Authlib Authlib.