CVE-2026-39998 Apache APISIX: Identity Injection via forward-auth Plugin Missing Header Cleanup
Attackers can spoof identity headers via the forward-auth plugin, bypassing authentication checks in Apache APISIX.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-39998?
CVE-2026-39998 is a medium-severity authentication bypass vulnerability in Apache APISIX, published on 19 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-20
Which versions are affected by CVE-2026-39998?
1 open source package ship an affected version, including apisix. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
apisix Bitnami | From 2.12.0 | 3.17.0 |
Products include Apache Apisix.
How do I fix CVE-2026-39998?
Upgrade apisix to 3.17.0 or later.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-39998 being exploited?
There is no known exploitation of CVE-2026-39998 in the wild and no public exploit code.
Other vulnerabilities in Apache APISIX
- CVE-2022-24112 Apache APISIX Authentication Bypass
- CVE-2022-25757 Apache APISIX: the body_schema check in request-validation plugin can be bypassed
- CVE-2026-31908 Apache APISIX: forward auth plugin allows header injection
- CVE-2026-75005 Apache APISIX: Unauthenticated CPU-exhaustion DoS
- CVE-2025-27446 Privilege escalation in Apache APISIX Java Plugin Runner
Sources
Also known as BIT-apisix-2026-39998, GHSA-86hq-f9pp-3cr9, MINI-g8rj-8f5g-4cqx.