CVE-2026-28498Authlib: Fail-Open Cryptographic Verification in OIDC Hash Binding
Descripción
Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to version 1.6.9, a library-level vulnerability was identified in the Authlib Python library concerning the validation of OpenID Connect (OIDC) ID Tokens. Specifically, the internal hash verification logic (_verify_hash) responsible for validating the at_hash (Access Token Hash) and c_hash (Authorization Code Hash) claims exhibits a fail-open behavior when encountering an unsupported or unknown cryptographic algorithm. This flaw allows an attacker to bypass mandatory integrity protections by supplying a forged ID Token with a deliberately unrecognized alg header parameter. The library intercepts the unsupported state and silently returns True (validation passed), inherently violating fundamental cryptographic design principles and direct OIDC specifications. This issue has been patched in version 1.6.9.
Datos: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Se publican tal como los indican las fuentes, en inglés.
Productos y versiones afectados
| Fabricante | Producto | Versiones | |
|---|---|---|---|
| ansible automation platform | 2.6 | — | |
| authlib | authlib | < 1.6.9 | |
| quay | 3.10 | — | |
| quay | 3.12 | — | |
| quay | 3.15 | — | |
| quay | 3.16 | — | |
| Red Hat | Lightspeed Core | — | |
| Red Hat | Red Hat Ansible Automation Platform 2 | all versions | |
| Red Hat | Red Hat Ansible Automation Platform 2.6 | all versions | |
| Red Hat | Red Hat OpenShift AI (RHOAI) | — | |
| Red Hat | Red Hat Quay 3.10 | all versions | |
| Red Hat | Red Hat Quay 3.12 | all versions | |
| Red Hat | Red Hat Quay 3.15 | all versions | |
| Red Hat | Red Hat Quay 3.16 | all versions | |
| Red Hat | Red Hat Satellite 6 | all versions |
Referencias y parches
- https://github.com/authlib/authlib/security/advisories/GHSA-m344-f55w-2m6j ExploitMitigationVendor Advisory
- https://github.com/authlib/authlib/commit/b9bb2b25bf8b7e01512d847a95c1749646eaa72b Patch
- https://github.com/authlib/authlib/releases/tag/v1.6.9 ProductRelease Notes
- https://access.redhat.com/errata/RHSA-2026:6309
- https://access.redhat.com/errata/RHSA-2026:6497
- https://access.redhat.com/errata/RHSA-2026:6567
- https://access.redhat.com/errata/RHSA-2026:6568
- https://access.redhat.com/errata/RHSA-2026:6720
- https://access.redhat.com/errata/RHSA-2026:6912
- https://access.redhat.com/security/cve/CVE-2026-28498
- https://bugzilla.redhat.com/show_bug.cgi?id=2448182
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-28498.json
Coincidencias CPE (NVD) (1)
cpe:2.3:a:authlib:authlib:*:*:*:*:*:*:*:*< 1.6.9