CVE-2026-28802

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.

Score

CVSS 3.1 9.8 Critical

Status

Modified - security-advisories@github.com

Published

2026-03-06

Last modified

2026-09-10

Weaknesses

CWE-347

Affected products

• Authlib (Authlib)
• Ansible Automation Platform (Redhat)
• Quay (Redhat)
• Satellite (Redhat)

References

• https://github.com/authlib/authlib/commit/a61c2acb807496e67f32051b5f1b1d5ccf8f0a75
• https://github.com/authlib/authlib/commit/b87c32ed07b8ae7f805873e1c9cafd1016761df7
• https://github.com/authlib/authlib/security/advisories/GHSA-7wc2-qxgw-g8gg
• 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