#VU123529 Improper authentication in authlib - CVE-2026-28802
Published: March 4, 2026
Vulnerability identifier: #VU123529
Vulnerability risk: High
CVSSv4.0: 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:Amber
CVE-ID: CVE-2026-28802
CWE-ID: CWE-287
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
authlib
authlib
Software vendor:
Authlib
Authlib
Description
The vulnerability allows a remote attacker to bypass authentication process.
The vulnerability exists due to improper verification of empty JWT signature. A remote attacker can bypass authentication process and gain unauthorized access to the application by passing a JWT token containing alg: none and an empty signature.
Remediation
Install updates from vendor's website.