CVE-2026-39998: Apache APISIX

High severity, CVSS 8.8. EPSS: 0.7% chance of exploitation in the next 30 days.

Improper Input Validation vulnerability in Apache APISIX. The attacker can take advantage of certain configuration in forward-auth plugin to spoof identity headers. This issue affects Apache APISIX: from 2.12.0 through 3.16.0. Users are recommended to upgrade to version 3.17.0, which fixes the issue.

Affected products

• Apache APISIX: from 2.12.0, before 3.17.0 (fixed in 3.17.0)

Published 2026-06-19. Last modified 2026-06-23.