CVE-2026-28802Authlib: Setting `alg: none` and a blank signature appears to bypass signature verification
Updated under an hour ago ()
Does this affect you?
It affects authlib and 3 other products. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
Do this next
Free account, 1 product
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.
- CVSS
- 7.7 HIGH (v4.0, CNA)CVSS: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:P
- Weakness (CWE)
- CWE-347
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- GitHub_M
- NVD analysis
- Modified
- Record last updated
- Sep 10, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
authlib authlib authlib:authlib (from the name) | from 1.6.5, < 1.6.7 | CNA record |
Red Hat Red Hat Ansible Automation Platform 2.6 redhat:ansible_automation_platform | from 1774417022 not affected | CISA ADP |
Red Hat Red Hat Quay 3.10 redhat:quay | from 1773971077 not affected | CISA ADP |
Red Hat Red Hat Satellite 6 redhat:satellite | 6 | CISA ADP |
authlib authlib authlib:authlib | from 1.6.5 before 1.6.7 | NVD |
References
- https://github.com/authlib/authlib/security/advisories/GHSA-7wc2-qxgw-g8ggx-refsource-confirm, exploit, vendor-advisory
- https://github.com/authlib/authlib/commit/a61c2acb807496e67f32051b5f1b1d5ccf8f0a75x-refsource-misc, patch
- https://github.com/authlib/authlib/commit/b87c32ed07b8ae7f805873e1c9cafd1016761df7x-refsource-misc, patch
- 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
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.