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.

Project Subscriptions

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Advisories

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Fixes

Solution

No solution given by the vendor.


Workaround

Customers can configure their external authentication backend to ignore client-supplied `X-Forwarded-*` / `X-Original-*` headers or ensure it only evaluates session tokens rather than forwarded paths.

History

Wed, 14 Oct 2026 15:00:00 +0000

Type Values Removed Values Added
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.
Title NGINX Ingress Controller vulnerability
Weaknesses CWE-290
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: f5

Published:

Updated: 2026-10-14T14:40:28.582Z

Reserved: 2026-09-30T21:56:14.620Z

Link: CVE-2026-94197

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-14T15:17:26.963

Modified: 2026-10-14T16:04:11.750

Link: CVE-2026-94197

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses