{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-124040", "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "state": "PUBLISHED", "assignerShortName": "VulnCheck", "dateReserved": "2026-11-06T19:11:14.928Z", "datePublished": "2026-11-06T19:14:48.975Z", "dateUpdated": "2026-11-06T19:14:48.975Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10", "shortName": "VulnCheck", "dateUpdated": "2026-11-06T19:14:48.975Z"}, "datePublic": "2026-03-18T00:00:00.000Z", "title": "CivetWeb through 1.16 HTTP/2 Use-After-Free via Stale Pseudo-Header State", "descriptions": [{"lang": "en", "value": "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."}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "Use After Free", "cweId": "CWE-416", "type": "CWE"}]}], "affected": [{"vendor": "civetweb", "product": "civetweb", "defaultStatus": "unaffected", "versions": [{"version": "0", "status": "affected", "versionType": "custom", "lessThanOrEqual": "1.16"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:civetweb_project:civetweb:*:*:*:*:*:*:*:*", "versionEndIncluding": "1.16"}]}]}], "metrics": [{"format": "CVSS", "cvssV4_0": {"version": "4.0", "vectorString": "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", "attackVector": "NETWORK", "attackComplexity": "HIGH", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 9.2, "baseSeverity": "CRITICAL"}}, {"format": "CVSS", "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH", "baseScore": 8.1, "baseSeverity": "HIGH"}}], "references": [{"url": "https://github.com/civetweb/civetweb/issues/1379", "tags": ["issue-tracking"], "name": "GitHub Issue #1379"}, {"url": "https://github.com/civetweb/civetweb", "tags": ["product"]}, {"url": "https://github.com/civetweb/civetweb/blob/v1.16/src/http2.inl#L1574-L1581", "tags": ["technical-description"]}, {"name": "VulnCheck Advisory: CivetWeb through 1.16 HTTP/2 Use-After-Free via Stale Pseudo-Header State", "tags": ["third-party-advisory"], "url": "https://www.vulncheck.com/advisories/civetweb-through-1.16-http-2-use-after-free-via-stale-pseudo-header-state"}], "credits": [{"lang": "en", "value": "PuH4ck3rX", "type": "finder"}, {"lang": "en", "value": "Lee Keon-Hyeong", "type": "reporter"}], "x_generator": {"engine": "vulncheck-endgame"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "civetweb", "vendor": "civetweb", "versions": [{"lessThanOrEqual": "1.16", "status": "affected", "version": "0", "versionType": "custom"}]}], "source": "disclosure@vulncheck.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-124040", "lastModified": "2026-11-06T20:17:22.347", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 5.9, "source": "disclosure@vulncheck.com", "type": "Primary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "HIGH", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 9.2, "baseSeverity": "CRITICAL", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "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", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "disclosure@vulncheck.com", "type": "Secondary"}]}, "published": "2026-11-06T20:17:22.203", "references": [{"source": "disclosure@vulncheck.com", "url": "https://github.com/civetweb/civetweb"}, {"source": "disclosure@vulncheck.com", "url": "https://github.com/civetweb/civetweb/blob/v1.16/src/http2.inl#L1574-L1581"}, {"source": "disclosure@vulncheck.com", "url": "https://github.com/civetweb/civetweb/issues/1379"}, {"source": "disclosure@vulncheck.com", "url": "https://www.vulncheck.com/advisories/civetweb-through-1.16-http-2-use-after-free-via-stale-pseudo-header-state"}], "sourceIdentifier": "disclosure@vulncheck.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-416"}], "source": "disclosure@vulncheck.com", "type": "Primary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,1.16]"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "civetweb", "source": "cna", "vendor": "civetweb"}, "product": "civetweb", "vendor": "civetweb_project"}], "created": "2026-11-06T20:45:07.131237+00:00", "updated": "2026-11-06T21:45:10.100451+00:00", "vendors": ["civetweb_project", "civetweb_project$PRODUCT$civetweb"]}