SB2026030442 - Authentication bypass in Authlib
Published: March 4, 2026
Security Bulletin ID
SB2026030442
CSH Severity
High
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Data manipulation
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Improper authentication (CVE-ID: CVE-2026-28802)
CWE-ID: CWE-287 - Improper Authentication
CVSSv4: 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
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 update from vendor's website.