{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-63385", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-07-16T17:39:30.171Z", "datePublished": "2026-08-20T17:55:36.214Z", "dateUpdated": "2026-08-20T17:55:36.214Z"}, "containers": {"cna": {"title": "Libevent: HTTP header handling bugs create risk of access control bypass.", "problemTypes": [{"descriptions": [{"cweId": "CWE-444", "lang": "en", "description": "CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')", "type": "CWE"}]}], "metrics": [{"cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "LOW", "subConfidentialityImpact": "LOW", "subIntegrityImpact": "LOW", "subAvailabilityImpact": "NONE", "baseScore": 9.2, "baseSeverity": "CRITICAL", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:L/SI:L/SA:N", "version": "4.0"}}], "references": [{"name": "https://github.com/libevent/libevent/security/advisories/GHSA-jcwh-pvf2-73p2", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/libevent/libevent/security/advisories/GHSA-jcwh-pvf2-73p2"}, {"name": "https://github.com/libevent/libevent/commit/758be0c0f69c1934ef9a84ab39e9f9e5fde2e6d0", "tags": ["x_refsource_MISC"], "url": "https://github.com/libevent/libevent/commit/758be0c0f69c1934ef9a84ab39e9f9e5fde2e6d0"}, {"name": "https://github.com/libevent/libevent/commit/9170dd35e64714613e8d13b290587cfc28e258e2", "tags": ["x_refsource_MISC"], "url": "https://github.com/libevent/libevent/commit/9170dd35e64714613e8d13b290587cfc28e258e2"}, {"name": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable", "tags": ["x_refsource_MISC"], "url": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable"}, {"name": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha", "tags": ["x_refsource_MISC"], "url": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha"}], "affected": [{"vendor": "libevent", "product": "libevent", "versions": [{"version": ">= 2.2.0-alpha, < 2.2.2-alpha", "status": "affected"}, {"version": "< 2.1.13", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-08-20T17:55:36.214Z"}, "descriptions": [{"lang": "en", "value": "Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has two HTTP parsing weaknesses in http.c. evhttp_decode_uri_internal decodes percent-encoded %00 bytes into literal NUL characters, which can cause downstream C string operations to truncate a path and bypass validation performed on a different representation. evhttp_header_is_valid_value also accepts obsolete line folding in header values containing carriage return or line feed characters, allowing a proxy and libevent to interpret headers differently and enabling header injection or access control bypass. The CRLF header acceptance is fixed in versions 2.1.13 and 2.2.2-alpha, but the reviewed patches do not clearly remediate the URI NUL-truncation condition."}], "source": {"advisory": "GHSA-jcwh-pvf2-73p2", "discovery": "UNKNOWN"}}}}

{}

{"affected": [{"affectedData": [{"product": "libevent", "vendor": "libevent", "versions": [{"status": "affected", "version": ">= 2.2.0-alpha, < 2.2.2-alpha"}, {"status": "affected", "version": "< 2.1.13"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Libevent is an event notification library. Prior to 2.1.13 and 2.2.2-alpha, libevent has two HTTP parsing weaknesses in http.c. evhttp_decode_uri_internal decodes percent-encoded %00 bytes into literal NUL characters, which can cause downstream C string operations to truncate a path and bypass validation performed on a different representation. evhttp_header_is_valid_value also accepts obsolete line folding in header values containing carriage return or line feed characters, allowing a proxy and libevent to interpret headers differently and enabling header injection or access control bypass. The CRLF header acceptance is fixed in versions 2.1.13 and 2.2.2-alpha, but the reviewed patches do not clearly remediate the URI NUL-truncation condition."}], "id": "CVE-2026-63385", "lastModified": "2026-08-20T18:16:36.543", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "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": "LOW", "subIntegrityImpact": "LOW", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:L/SI:L/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": "LOW", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-08-20T18:16:36.543", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/libevent/libevent/commit/758be0c0f69c1934ef9a84ab39e9f9e5fde2e6d0"}, {"source": "security-advisories@github.com", "url": "https://github.com/libevent/libevent/commit/9170dd35e64714613e8d13b290587cfc28e258e2"}, {"source": "security-advisories@github.com", "url": "https://github.com/libevent/libevent/releases/tag/release-2.1.13-stable"}, {"source": "security-advisories@github.com", "url": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha"}, {"source": "security-advisories@github.com", "url": "https://github.com/libevent/libevent/security/advisories/GHSA-jcwh-pvf2-73p2"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-444"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[2.2.0-alpha,2.2.2-alpha)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,2.1.13)"}}], "enrichment": {"confidence": 81.0, "confidence_source": "matching", "scores": [{"score": 81.0, "source": "matching"}]}, "original": {"product": "libevent", "source": "cna", "vendor": "libevent"}, "product": "libevent", "vendor": "libevent_project"}], "created": "2026-08-21T02:15:04.424285+00:00", "updated": "2026-08-21T13:01:01.455001+00:00", "vendors": ["libevent_project", "libevent_project$PRODUCT$libevent"]}