High 8.8Published Oct 14, 2026

CVE-2026-91184NGINX Gateway Fabric vulnerability

Updated under an hour ago (2026-10-19 08:23 UTC)

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It affects F5 NGINX Gateway Fabric. Add what you run to find out whether that includes you.

EPSS puts the chance of exploitation in the next 30 days at 0.48%, higher than 40% of scored CVEs.

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Every CVE for F5 NGINX Gateway Fabric

Exploited in the last 30 days

Description NGINX Gateway Fabric has a vulnerability when it renders the spec.basic.realm (and spec.jwt.realm) field of a namespaced AuthenticationFilter verbatim, unescaped and unvalidated, into the shared data-plane nginx.conf as auth_basic "<realm>";. A namespaced authenticated attacker that configures AuthenticationFilter CRD to an HTTPRoute/GRPCRoute on a shared Gateway can craft a realm value that closes the quoted directive and the enclosing location {} block and injects arbitrary NGINX directives into that Gateway's data-plane config. Impact A remote authenticated attacker can send crafted requests to configure NGINX Gateway Fabric AuthenticationFilter CRD and may be able to read every co-located tenant's mounted secrets, SSRF via proxy_pass, reading the pod ServiceAccount token, or hijacking other tenants' routes. There is no data plane exposure; this is a control plane issue only. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

CVSS: 8.8 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-76
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): 0.48% (percentile 40)
Assigned by: f5
NVD analysis: Awaiting Analysis
Record last updated: Oct 15, 2026
First seen by InfoSec Signals: Oct 14, 2026

Affected products

Affected products

F5 NGINX Gateway Fabric f5:nginx_gateway_fabric (from the name)	from 2.4.0 before 2.8.0	CNA record

References

https://my.f5.com/manage/s/article/K000162609vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.