Read the docs
TI-2026-22996 Aliases CVE-2026-28802GHSA-7wc2-qxgw-g8gg

Authlib: Setting `alg: none` and a blank signature appears to bypass signature verification

Priority MEDIUM 40CWE-347Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Security bypass
Confidentiality · integrity · availability
None · High · None
Fix status
Partial Red Hat: 6 fixed, 1 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-347.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00538 45th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial authlib (authlib): 1.6.7authlib (PyPI): 1.6.7Red Hat: 7 advisoriesRed Hat: 6 fixed, 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
authlibauthlib1.6.5 to before 1.6.71.6.7Patch availableCNA
—authlib (PyPI)1.6.5 to before 1.6.71.6.7Patch availableGHSA-7wc2-qxgw-g8gg
  • authlib Vendorauthlib Affected 1.6.5 to before 1.6.7 Fixed in 1.6.7 Patch available CNA
  • authlib (PyPI) Vendor— Affected 1.6.5 to before 1.6.7 Fixed in 1.6.7 Patch available GHSA-7wc2-qxgw-g8gg

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:authlib:authlib:*:*:*:*:*:*:*:*1.6.5 to before 1.6.7Vulnerableauthlib
  • cpe:2.3:a:authlib:authlib:*:*:*:*:*:*:*:* Versions 1.6.5 to before 1.6.7 Vulnerable ·authlib

Remediation

  • Fix · CNA authlib (authlib) Fixed in 1.6.7
  • Fix · GHSA-7wc2-qxgw-g8gg authlib (PyPI) Fixed in 1.6.7 Advisory →

Red Hat 7 advisories

  • RHSA-2026:19375 Released 2026-05-19 · Red Hat rating Important
    Red Hat Quay 3.16.4
    • Red Hat Quay 3.16 registry.redhat.io/quay/quay-rhel9
  • RHSA-2026:6568 Released 2026-04-03 · Red Hat rating Important
    Red Hat Quay 3.15.4
    • Red Hat Quay 3.15 registry.redhat.io/quay/quay-rhel8
  • RHSA-2026:6404 Released 2026-04-01 · Red Hat rating Important
    Red Hat Ansible Automation Platform 2.6 Container Release Update
    • Red Hat Ansible Automation Platform 2.6 registry.redhat.io/ansible-automation-platform-26/gateway-rhel9, registry.redhat.io/ansible-automation-platform-26/hub-rhel9, registry.redhat.io/ansible-automation-platform-26/lightspeed-chatbot-rhel9 +2
Show 4 more Red Hat advisories
  • RHSA-2026:6309 Released 2026-03-31 · Red Hat rating Important
    Red Hat Ansible Automation Platform 2.6 Container Release Update
    • Red Hat Ansible Automation Platform 2.6 registry.redhat.io/ansible-automation-platform-26/gateway-rhel9, registry.redhat.io/ansible-automation-platform-26/hub-rhel9, registry.redhat.io/ansible-automation-platform-26/lightspeed-chatbot-rhel9 +2
  • RHSA-2026:5665 Released 2026-03-24 · Red Hat rating Important
    Red Hat Quay 3.10.19
    • Red Hat Quay 3.10 registry.redhat.io/quay/quay-rhel8
  • RHSA-2026:5168 Released 2026-03-19 · Red Hat rating Important
    Red Hat Quay 3.9.19
    • Red Hat Quay 3.9 registry.redhat.io/quay/quay-rhel8
  • RHSA-2026:4942 Released 2026-03-18 · Red Hat rating Important
    Red Hat Quay 3.12.15
    • Red Hat Quay 3.12 registry.redhat.io/quay/quay-rhel8

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Satellite 6AffectedNo fix yet
Red Hat Ansible Automation Platform 2.6Fixed RHSA-2026:6309
Red Hat Quay 3.10Fixed RHSA-2026:5665
Red Hat Quay 3.12Fixed RHSA-2026:4942
Red Hat Quay 3.15Fixed RHSA-2026:6568
Red Hat Quay 3.16Fixed RHSA-2026:19375
Red Hat Quay 3.9Fixed RHSA-2026:5168
Not affected: 6 products
  • Red Hat Ansible Automation Platform 2.6
  • Red Hat Quay 3.10
  • Red Hat Quay 3.12
  • Red Hat Quay 3.15
  • Red Hat Quay 3.16
  • Red Hat Quay 3.9

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-28802
  2. 2026-10-03 Alias added: GHSA-7wc2-qxgw-g8gg

References

Exploit 1

Patch 2

Advisory 1

Other 1

  • TI-2026-22305 Authlib JWS JWK Header Injection: Signature Verification Bypass CVSS 3.1CRITICAL 9.1
  • TI-2026-79518 Authlib fix bypass lets attackers forge HS256 tokens with PEM keys CVSS 3.1CRITICAL 9.1
  • TI-2025-36973 Authlib: JWS/JWT accepts unknown crit headers (RFC violation → possible authz bypass) CVSS 3.1HIGH 7.5
  • TI-2024-25068 lepture Authlib before 1.3.1 has algorithm confusion with asymmetric public keys. CVSS 3.1HIGH 7.5
  • TI-2025-41738 Authlib: 1-click Account Takeover CVSS 3.1HIGH 8.8
  • TI-2026-22761 Authlib: Fail-Open Cryptographic Verification in OIDC Hash Binding CVSS 4.0HIGH 8.2
See all 18 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences