{"affected":[{"defaultStatus":"unaffected","product":"civetweb","source":"CNA: VulnCheck","vendor":"civetweb","versions":[{"lessThanOrEqual":"1.16","status":"affected","version":"0","versionType":"custom"}]}],"cveId":"CVE-2026-124040","cwes":["CWE-416"],"description":"CivetWeb through 1.16, when built with USE_HTTP2 and enable_http2 on, contains a use-after-free vulnerability in handle_http2() that retains freed :method and :path pointers. Unauthenticated remote attackers can send a later HEADERS frame omitting these pseudo-headers to influence request method or path seen by access rules, or crash the server.","epss":{"date":"2026-11-10","percentile":0.44162,"score":0.00514},"exploits":[],"kev":null,"metrics":[{"score":9.2,"severity":"critical","source":"CNA: VulnCheck","vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","version":"4.0"},{"score":8.1,"severity":"high","source":"CNA: VulnCheck","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},{"score":9.2,"severity":"critical","source":"NVD: disclosure@vulncheck.com","vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/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","version":"4.0"},{"score":8.1,"severity":"high","source":"NVD: disclosure@vulncheck.com","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}],"modifiedAt":1794367496121,"publishedAt":1793992488975,"references":[{"source":"CNA: VulnCheck","tags":["issue-tracking"],"url":"https://github.com/civetweb/civetweb/issues/1379"},{"source":"CNA: VulnCheck","tags":["product"],"url":"https://github.com/civetweb/civetweb"},{"source":"CNA: VulnCheck","tags":["technical-description"],"url":"https://github.com/civetweb/civetweb/blob/v1.16/src/http2.inl#L1574-L1581"},{"source":"CNA: VulnCheck","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/civetweb-through-1.16-http-2-use-after-free-via-stale-pseudo-header-state"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://github.com/civetweb/civetweb"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://github.com/civetweb/civetweb/blob/v1.16/src/http2.inl#L1574-L1581"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://github.com/civetweb/civetweb/issues/1379"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://www.vulncheck.com/advisories/civetweb-through-1.16-http-2-use-after-free-via-stale-pseudo-header-state"}],"remediation":[],"revision":"913bcd9adcd851d991eaed0e9349a4acb88c1c5bfd931d612bab6c75c4f29c50","sources":[{"modifiedAt":1794367496121,"name":"CNA: VulnCheck","retrievedAt":1794370128414,"url":"https://www.cve.org/CVERecord?id=CVE-2026-124040"},{"modifiedAt":1793996242347,"name":"NVD","retrievedAt":1794011243624,"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-124040"},{"modifiedAt":null,"name":"FIRST EPSS","retrievedAt":1794370160214,"url":"https://api.first.org/data/v1/epss?cve=CVE-2026-124040"}],"ssvc":{"assessedAt":1794367486139,"automatable":"no","exploitation":"none","source":"ADP: CISA-ADP","technicalImpact":"total"},"status":"published","title":"CivetWeb through 1.16 HTTP/2 Use-After-Free via Stale Pseudo-Header State","updatedAt":1794370160214}