{"id":"EM-20261107-L8SX","url":"https://cyber.eventmonitor.net/incident/EM-20261107-L8SX/critical-fiber-admin-vulnerability-cve-2026-121491/","type":"cve","title":"Critical Fiber Admin Vulnerability (CVE-2026-121491)","subtitle":"CVE-2026-121491","subject":"CVE-2026-121491","status":"Developing","severity":"critical","affected":[],"headline":null,"born":"2026-11-07T06:31:24.000Z","firstSignal":"2026-11-07T06:16:58.280Z","lastSignal":"2026-11-07T06:31:24.000Z","updated":"2026-11-07T20:02:50.207Z","revision":1,"life":[{"status":"Born","at":"2026-11-07T06:31:24.000Z","why":"second independent source: C29 CIRCL Vulnerability-Lookup"},{"status":"Developing","at":"2026-11-07T06:31:24.000Z","why":"signals keep joining"}],"changeLog":[{"at":"2026-11-07T06:16:58.280Z","what":"First signal: C6 NVD CVE API 2.0"},{"at":"2026-11-07T06:31:24.000Z","what":"Born: second source, C29 CIRCL Vulnerability-Lookup. Page EM-20261107-L8SX created."}],"stages":[{"name":"Disclosed","at":"2026-11-07T06:16:58.280Z","detail":"C6 NVD published"},{"name":"Scored","at":"2026-11-07T06:16:58.280Z","detail":"CVSS 9 · EPSS 0.2%"},{"name":"Exploited","at":null,"detail":"No exploitation reported"},{"name":"Advisories","at":null,"detail":"None yet"},{"name":"Vendor Response","at":null,"detail":"None in sources yet"},{"name":"Resolved","at":null,"detail":"After 14 quiet days"}],"signals":[{"at":"2026-11-07T06:16:58.280Z","source":"C6","sourceName":"NVD CVE API 2.0","role":"Database","severity":4,"title":"CVE-2026-121491 (CVSS 9)","text":"The Fiber Admin WordPress plugin before 4.0.1 does not validate or escape a request header before writing it into a PHP file it regenerates on an unprotected admin hook, allowing unauthenticated attackers to execute arbitrary code when its custom database error page is enabled and they win a race against an administrator saving its settings.","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-121491"},{"at":"2026-11-07T06:31:24.000Z","source":"C29","sourceName":"CIRCL Vulnerability-Lookup","role":"Database","severity":2,"title":"GHSA-qr57-vj96-mp6j / CVE-2026-121491","text":"The Fiber Admin WordPress plugin before 4.0.1 does not validate or escape a request header before writing it into a PHP file it regenerates on an unprotected admin hook, allowing unauthenticated attackers to execute arbitrary code when its custom database error page is enabled and they win a race…","url":"https://vulnerability.circl.lu/vuln/GHSA-qr57-vj96-mp6j"}],"crowd":[],"reference":{"nvd":{"published":"2026-11-07T06:16:58.280","score":9,"severity":"CRITICAL","desc":"The Fiber Admin WordPress plugin before 4.0.1 does not validate or escape a request header before writing it into a PHP file it regenerates on an unprotected admin hook, allowing unauthenticated attackers to execute arbitrary code when its custom database error page is enabled and they win a race…","product":"","seen":1794081770207},"kev":null,"epss":{"epss":0.00224,"pct":0.13142,"at":1794081770207},"p0":false},"mergedInto":null,"publisher":"Event Monitor Cyber"}