CVE-2026-63380
Full vulnerability record from the local CVENow database.
Description
Libevent is an event notification library. Prior to 2.2.2-alpha, libevent can dereference invalid list pointers in ws.c when evws_new_session enters its error path after evhttp_start_ws_ succeeds but bufferevent_enable_locking_ fails. evws_connection_free sees a non-null http_server and unconditionally calls TAILQ_REMOVE even though the session was never inserted into http_server->ws_sessions. A local caller able to induce this allocation or locking failure can crash the process. This issue is fixed in version 2.2.2-alpha.
Severity
MEDIUM
CVSS score
5.7
(v4.0)
Vulnerability status
Awaiting Analysis
Source identifier
Published
2026-08-20 18:16:35.357000
Last modified
2026-10-26 10:10:00.140000
View original CVE JSON
{
"id": "CVE-2026-63380",
"sourceIdentifier": "[email protected]",
"published": "2026-08-20T18:16:35.357",
"lastModified": "2026-10-26T10:10:00.140",
"vulnStatus": "Awaiting Analysis",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "Libevent is an event notification library. Prior to 2.2.2-alpha, libevent can dereference invalid list pointers in ws.c when evws_new_session enters its error path after evhttp_start_ws_ succeeds but bufferevent_enable_locking_ fails. evws_connection_free sees a non-null http_server and unconditionally calls TAILQ_REMOVE even though the session was never inserted into http_server->ws_sessions. A local caller able to induce this allocation or locking failure can crash the process. This issue is fixed in version 2.2.2-alpha."
},
{
"lang": "es",
"value": "Libevent es una biblioteca de notificación de eventos. Anterior a 2.2.2-alpha, libevent puede desreferenciar punteros de lista inválidos en ws.c cuando evws_new_session entra en su ruta de error después de que evhttp_start_ws_ tiene éxito pero bufferevent_enable_locking_ falla. evws_connection_free ve un http_server no nulo y llama incondicionalmente a TAILQ_REMOVE aunque la sesión nunca fue insertada en http_server -> ws_sessions. Un llamador local capaz de inducir este fallo de asignación o bloqueo puede bloquear el proceso. Este problema está solucionado en la versión 2.2.2-alpha."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "libevent",
"product": "libevent",
"versions": [
{
"version": "< 2.2.2-alpha",
"status": "affected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV40": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "4.0",
"vectorString": "CVSS:4.0/AV:L/AC:H/AT:P/PR:L/UI:N/VC:N/VI:N/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",
"baseScore": 5.7,
"baseSeverity": "MEDIUM",
"attackVector": "LOCAL",
"attackComplexity": "HIGH",
"attackRequirements": "PRESENT",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE",
"vulnAvailabilityImpact": "HIGH",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"subAvailabilityImpact": "NONE",
"exploitMaturity": "NOT_DEFINED",
"confidentialityRequirement": "NOT_DEFINED",
"integrityRequirement": "NOT_DEFINED",
"availabilityRequirement": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"valueDensity": "NOT_DEFINED",
"vulnerabilityResponseEffort": "NOT_DEFINED",
"providerUrgency": "NOT_DEFINED"
}
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-08-25T15:10:47.662356Z",
"id": "CVE-2026-63380",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-416"
},
{
"lang": "en",
"value": "CWE-476"
}
]
}
],
"references": [
{
"url": "https://github.com/libevent/libevent/commit/825c18bd99f556b59d61200523237f264d5cc734",
"source": "[email protected]"
},
{
"url": "https://github.com/libevent/libevent/releases/tag/release-2.2.2-alpha",
"source": "[email protected]"
},
{
"url": "https://github.com/libevent/libevent/security/advisories/GHSA-3rpf-frgx-xq34",
"source": "[email protected]"
},
{
"url": "https://github.com/libevent/libevent/security/advisories/GHSA-3rpf-frgx-xq34",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
}
]
}