CVE-2026-28802
High
High exploit probability or critical severity with a known exploit.
CVSS base
9.8
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS — probability of exploitation (30 days)
0.4%
36.3th percentile
CISA KEV
Not listed
Weakness / dates
CWE-347
Published 2026-03-06 · modified 2026-09-10
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.
Affected
References
- https://github.com/authlib/authlib/commit/a61c2acb807496e67f32051b5f1b1d5ccf8f0a75
- https://github.com/authlib/authlib/commit/b87c32ed07b8ae7f805873e1c9cafd1016761df7
- exploit 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