CVSS 4.0
7.7 highCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:PCVE-2026-28802
High (7.7) in authlib authlib. EPSS 0.5% chance of exploitation in the next 30 days. Fixed in authlib 1.6.7.
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.
Severity
CVSS 3.1
9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- EPSS
- 0.5% chance of exploitation in the next 30 days; higher than 43% of CVEs (scores of 2026-10-31)
- CWE
- CWE-347
- Published
- Modified
- Record from
- the NVD, synced
Affected
- authlib:authlib
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-7wc2-qxgw-g8gg | PyPI | authlib | >=1.6.5 <1.6.7 | 1.6.7 |
| PYSEC-2026-2118 | PyPI | authlib | >=1.6.5 <1.6.7 | 1.6.7 |
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