CVE Vulnerabilities

CVE-2026-28802

Improper Verification of Cryptographic Signature

Published: Mar 06, 2026 | Modified: Mar 09, 2026
CVSS 3.x
9.8
CRITICAL
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 2.x
RedHat/V2
RedHat/V3
9.1 IMPORTANT
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Ubuntu
MEDIUM
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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.

Weakness

The product does not verify, or incorrectly verifies, the cryptographic signature for data.

Affected Software

NameVendorStart VersionEnd Version
AuthlibAuthlib1.6.5 (including)1.6.7 (excluding)

References