Vulnerability · Published Oct 14, 2026 · Assigned by f5

CVE-2026-94197NGINX Ingress Controller vulnerability

High 7.5

In plain English

A high-severity authentication bypass by spoofing in NGINX Ingress Controller from F5. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 34% of all known vulnerabilities).

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.4%top 66.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

An authentication and authorization bypass vulnerability exists in F5 NGINX Kubernetes Ingress Controller (NIC) when configured with the `ExternalAuth` policy or Ingress external authentication. Client-supplied X-Forwarded-Prefix, X-Forwarded-URI, X-Original-URI, and X-Forwarded-Method routing and method headers are forwarded unsanitized into the internal authentication subrequest (handled by the NGINX auth_request directive). As a result, an unauthenticated, remote attacker may spoof request attributes evaluated by the external authentication provider. 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 products (as reported)

Vendor	Product	Versions
F5	NGINX Ingress Controller	5.5.0 – before 5.7.0

Weakness: CWE-290 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

References

https://my.f5.com/manage/s/article/K000162611 vendor-advisory