CVE-2026-104939: NGINX Ingress Controller vulnerability
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.
Affected Software
Event History
Frequently Asked Questions
Which deployments are exposed to this issue?
Deployments using F5 NGINX Ingress Controller to implement an externalAuth policy for ingress are affected by the described condition. The issue is limited to the data plane; no control plane exposure is identified.
What does an attacker need to exploit it?
A remote attacker does not need authentication or user interaction. Exploitation involves the controller mishandling an HTTP response from an OAuth identity provider before external authentication completes.
What is the potential impact?
An attacker may obtain unauthenticated access to paths that are intended to be protected by external authentication. The stated impact is confidentiality exposure; integrity and availability impacts are not identified.
Are unsupported software versions covered by the evaluation?
No. Software versions that have reached End of Technical Support are not evaluated.