{"schemaVersion":3,"id":"CVE-2026-91184","aliases":[],"status":"published","duplicateOf":null,"title":null,"description":"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_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.","dates":{"published":"2026-10-14T14:40:27.849Z","modified":"2026-10-15T10:31:15.425Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":8.8,"severity":"high","version":"3.1","versionLabel":"v3.1","source":"CVE.org","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","computed":false,"selection":"backend-summary"},"metrics":[{"version":"4.0","versionLabel":"v4.0","source":"CVE.org","score":8.7,"severity":"high","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"CVE.org","score":8.8,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","exploitability":null,"impact":null,"computed":false},{"version":"4.0","versionLabel":"v4.0","source":"NVD","score":8.7,"severity":"high","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"NVD","score":8.8,"severity":"high","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.00482,"percentile":0.40207,"severity":"low","asOf":"2026-10-19T00:00:00.000Z","change":{"pp":null,"baselineDate":null,"baselineScore":null},"history":[{"date":"2026-10-15T00:00:00.000Z","score":0.00482,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00482,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00482,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00482,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00482,"percentile":0.40207}],"last30":[{"date":"2026-10-15T00:00:00.000Z","score":0.00482,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00482,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00482,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00482,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00482,"percentile":0.40207}]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[{"id":"CWE-76","name":"Improper Neutralization of Equivalent Special Elements","description":"The product correctly neutralizes certain special elements, but it improperly neutralizes equivalent special elements.","type":"weakness","status":"Draft","abstraction":"Base","likelihoodOfExploit":"High","url":"https://cwe.mitre.org/data/definitions/76.html"}],"affected":[{"vendor":"f5","product":"nginx gateway fabric","name":"NGINX Gateway Fabric","label":"nginx gateway fabric","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"≥ 2.4.0, < 2.8.0","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ 2.4.0, < 2.8.0","eol":null,"hubHref":"/vendor/f5/nginx_gateway_fabric"}],"affectedCount":1,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://my.f5.com/manage/s/article/K000162609","label":"my.f5.com/manage/s/article/K000162609","hostname":"my.f5.com","tags":["Vendor Advisory"]}],"lineage":{"upstream":[],"downstream":[],"duplicates":[],"related":[]},"timeline":[{"kind":"published","date":"2026-10-14T14:40:27.849Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-10-15T10:31:15.425Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":35,"level":"medium","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-19T16:43:30.249Z","stale":false,"partial":false}}