Improper Verification of Cryptographic Signature in authlib - CVE-2026-27962
Published: March 17, 2026
Vulnerability identifier: #VU124066
CSH Severity: Critical
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Red
CVE-ID: CVE-2026-27962
CWE-ID: CWE-347
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Authlib
Affected software:
authlib
authlib
Detailed vulnerability description
The vulnerability allows a remote attacker to bypass authentication checks.
The vulnerability exists due to improper validation of HTTP headers. A remote attacker can forge arbitrary JWT tokens that pass signature verification and bypass authentication checks.
How to mitigate CVE-2026-27962
Install updates from vendor's website.