CVE-2026-39999 PUBLISHED

Apache APISIX: JWT Algorithm Confusion allows authentication bypass

Assigner: apache
Reserved: 08.04.2026 Published: 19.06.2026 Updated: 19.06.2026

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 v3.17.0, which fixes the issue.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N
CVSS Score: 7

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	High
Attack Complexity	Low	Integrity	None	Integrity	High
Attack Requirements	Present	Availability	None	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

Product Status

Vendor	Apache Software Foundation
Product	Apache APISIX
Versions	Default: unaffected affected from 2.2 to 3.16.0 (incl.)

Credits

Marco Capuano reporter

References

https://lists.apache.org/thread/nfopt8cnxd3k0rs1oxtr7lzxrdw4mojq

Problem Types

CWE-290 Authentication Bypass by Spoofing CWE