Description (CNA)
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.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| authlib / authlib | affected >= 1.6.5, < 1.6.7 |
CWE
CWE-347
References
- https://github.com/authlib/authlib/security/advisories/GHSA-7wc2-qxgw-g8gg
- https://github.com/authlib/authlib/commit/a61c2acb807496e67f32051b5f1b1d5ccf8f0a75
- https://github.com/authlib/authlib/commit/b87c32ed07b8ae7f805873e1c9cafd1016761df7
ADP enrichment
No English description supplied.
No references supplied.
A flaw was found in Authlib, a Python library for building OAuth and OpenID Connect servers. A remote attacker can exploit this vulnerability by crafting a malicious JSON Web Token (JWT) with a "none" algorithm and an empty signature. This bypasses the expected signature verification, potentially allowing the attacker to forge tokens and gain unauthorized access or perform unauthorized actions within applications using Authlib.
- 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
- https://access.redhat.com/errata/RHSA-2026:6309
- https://access.redhat.com/errata/RHSA-2026:5665
- https://access.redhat.com/errata/RHSA-2026:4942
- https://access.redhat.com/errata/RHSA-2026:6568
- https://access.redhat.com/errata/RHSA-2026:19375
- https://access.redhat.com/errata/RHSA-2026:5168