CVE-2026-104939 NGINX Ingress Controller vulnerability
Attackers can bypass external authentication to access protected paths in NGINX Ingress Controller when externalAuth is configured.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-104939?
CVE-2026-104939 is a high-severity authentication bypass vulnerability in F5 NGINX Ingress Controller, published on 14 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Description NGINX Ingress Controller has a vulnerability when implementing an externalAuth policy for ingress. NGINX Ingress Controller may mishandle the HTTP response from an OAuth IdP and allow an attacker to acquire unauthenticated access to protected paths before the proper external authentication can happen.
Impact This vulnerability may allow remote attackers
unauthenticated
access to protected
paths. There is no control plane exposure; this is a data plane issue only.
Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Weakness: CWE-303
Which versions are affected by CVE-2026-104939?
How do I fix CVE-2026-104939?
No fix has been published for CVE-2026-104939 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-104939 being exploited?
There is no known exploitation of CVE-2026-104939 in the wild and no public exploit code.
Sources
Also known as GHSA-qcp7-h72p-6whw.