CVE-2026-28802

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 v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/authlib/authlib/commit/a61c2acb807496e67f32051b5f1b1d5ccf8f0a75	Patch
https://github.com/authlib/authlib/commit/b87c32ed07b8ae7f805873e1c9cafd1016761df7	Patch
https://github.com/authlib/authlib/security/advisories/GHSA-7wc2-qxgw-g8gg	Exploit Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:authlib:authlib:*:*:*:*:*:*:*:*

History

09 Mar 2026, 21:20

Type	Values Removed	Values Added
References	~~() https://github.com/authlib/authlib/commit/a61c2acb807496e67f32051b5f1b1d5ccf8f0a75 -~~	() https://github.com/authlib/authlib/commit/a61c2acb807496e67f32051b5f1b1d5ccf8f0a75 - Patch
References	~~() https://github.com/authlib/authlib/commit/b87c32ed07b8ae7f805873e1c9cafd1016761df7 -~~	() https://github.com/authlib/authlib/commit/b87c32ed07b8ae7f805873e1c9cafd1016761df7 - Patch
References	~~() https://github.com/authlib/authlib/security/advisories/GHSA-7wc2-qxgw-g8gg -~~	() https://github.com/authlib/authlib/security/advisories/GHSA-7wc2-qxgw-g8gg - Exploit, Vendor Advisory
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 9.8
First Time		Authlib authlib Authlib
CPE		cpe:2.3:a:authlib:authlib::::::::

06 Mar 2026, 07:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-03-06 07:16

Updated : 2026-03-09 21:20

NVD link : CVE-2026-28802

Mitre link : CVE-2026-28802

CVE.ORG link : CVE-2026-28802

JSON object : View

Products Affected

authlib

authlib

CWE

CWE-347

Improper Verification of Cryptographic Signature

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