Vulnerability · Published Oct 14, 2026 · Assigned by f5

CVE-2026-104939NGINX Ingress Controller vulnerability

High 7.5

In plain English

A high-severity security flaw 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 32% of all known vulnerabilities).

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.4%top 68.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

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.

Affected products (as reported)

Vendor	Product	Versions
F5	NGINX Ingress Controller	5.6.0 – before 5.7.0

Weakness: CWE-303 · 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/K000162617 vendor-advisory