5.8
MEDIUM CVSS 4.0
CVE-2026-39998
Apache APISIX: Identity Injection via forward-auth Plugin Missing Header Cleanup
Description

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.

INFO

Published Date :

June 19, 2026, 1:04 p.m.

Last Modified :

June 19, 2026, 1:05 p.m.

Remotely Exploit :

Yes !

Source :

apache
Affected Products

The following products are affected by CVE-2026-39998 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Apache apisix
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 4.0 MEDIUM f0158376-9dc2-43b6-827c-5f631a4d8d09
Solution
Upgrade Apache APISIX to version 3.17.0 to fix identity header spoofing.
  • Upgrade Apache APISIX to version 3.17.0.
  • Review forward-auth plugin configurations.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-39998 vulnerability anywhere in the article.

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.