CVE-2026-39999: Apache APISIX: JWT Algorithm Confusion allows authentication bypass

[Abhishek Choudhary <shreemaanabhishek () apache org>]

Severity: 

Affected versions:

- Apache APISIX 2.2 through 3.16.0

Description:

Authentication Bypass by Spoofing vulnerability in Apache APISIX.

The attacker can completely bypass authentication capitalising on certain configurations of jwt-auth plugin.
This issue affects Apache APISIX: from v2.2 through v3.16.0.

Users are recommended to upgrade to version v3.16.1, which fixes the issue.

Credit:

Marco Capuano (reporter)

References:

https://apisix.apache.org
https://www.cve.org/CVERecord?id=CVE-2026-39999