Input validation error in Apache APISIX - CVE-2026-39998
Published: August 25, 2026
Vulnerability identifier: #VU145240
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-39998
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to spoof identity headers.
The vulnerability exists due to improper input validation in the forward-auth plugin when processing requests under certain configurations. A remote attacker can send crafted headers to spoof identity headers.
Exploitation is possible only when the forward-auth plugin is used with certain configurations.
Affected software
Apache APISIX
How to mitigate CVE-2026-39998
Install security update from vendor's website.
Apache APISIX - update to 3.16.1