{"id":"CVE-2026-91184","title":"Description\n\nNGINX 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…","summary":"Description\n\nNGINX 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…","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-76"],"vendor":"F5","product":"NGINX Gateway Fabric","affected":["nginx_gateway_fabric >= 2.4.0 < 2.8.0"],"published":"2026-10-14","updated":"2026-10-15","sourceUpdated":"2026-10-15T11:18:03.460","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-91184","references":[{"url":"https://my.f5.com/manage/s/article/K000162609","label":"f5sirt@f5.com"}],"tags":["nvd","cve.org"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-15T03:57:02.149250Z"},"ingestedAt":"2026-10-14T15:36:14.033Z","epss":0.00482,"epssPercentile":0.41376,"slug":"CVE-2026-91184","body":"## Overview\n\nDescription\n\nNGINX 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. \n\nImpact\n\nA 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.\n\n\n\n\n\n\nNote: Software versions which have reached End of Technical Support (EoTS) are not evaluated.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":48.4,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}