CVE-2026-56412
Full vulnerability record from the local CVENow database.
Description
libexpat before 2.8.2 does not consider XML_TOK_DATA_CHARS in doCdataSection and thus lacks handler call depth tracking for various calls from within handlers in cases of a policy violation. Thus, a use-after-free can occur. NOTE: this issue exists because of an incomplete fix for CVE-2026-50219.
Severity
MEDIUM
CVSS score
5.9
(v3.1)
Vulnerability status
Analyzed
Source identifier
Published
2026-06-21 17:16:44.657000
Last modified
2026-10-25 23:10:00.167000
View original CVE JSON
{
"id": "CVE-2026-56412",
"sourceIdentifier": "[email protected]",
"published": "2026-06-21T17:16:44.657",
"lastModified": "2026-10-25T23:10:00.167",
"vulnStatus": "Analyzed",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "libexpat before 2.8.2 does not consider XML_TOK_DATA_CHARS in doCdataSection and thus lacks handler call depth tracking for various calls from within handlers in cases of a policy violation. Thus, a use-after-free can occur. NOTE: this issue exists because of an incomplete fix for CVE-2026-50219."
},
{
"lang": "es",
"value": "libexpat antes de la versión 2.8.2 no considera XML_TOK_DATA_CHARS en doCdataSection y, por lo tanto, carece de seguimiento de la profundidad de las llamadas a los gestores para varias llamadas desde dentro de los gestores en casos de una violación de política. Así, un uso después de liberación puede ocurrir. NOTA: este problema existe debido a una corrección incompleta para CVE-2026-50219."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "libexpat project",
"product": "libexpat",
"defaultStatus": "unaffected",
"versions": [
{
"version": "0",
"lessThan": "2.8.2",
"versionType": "semver",
"status": "affected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L",
"baseScore": 4.9,
"baseSeverity": "MEDIUM",
"attackVector": "LOCAL",
"attackComplexity": "HIGH",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "LOW",
"integrityImpact": "LOW",
"availabilityImpact": "LOW"
},
"exploitabilityScore": 1.4,
"impactScore": 3.4
},
{
"source": "[email protected]",
"type": "Primary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L",
"baseScore": 5.9,
"baseSeverity": "MEDIUM",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "LOW",
"integrityImpact": "LOW",
"availabilityImpact": "LOW"
},
"exploitabilityScore": 2.5,
"impactScore": 3.4
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-06-22T16:30:58.502417Z",
"id": "CVE-2026-56412",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-416"
}
]
}
],
"configurations": [
{
"nodes": [
{
"operator": "OR",
"negate": false,
"cpeMatch": [
{
"vulnerable": true,
"criteria": "cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:*",
"versionEndExcluding": "2.8.2",
"matchCriteriaId": "E3A57811-3797-4D35-A4AC-E1AB3CE6F1F3"
}
]
}
]
}
],
"references": [
{
"url": "https://github.com/libexpat/libexpat/pull/1278",
"source": "[email protected]",
"tags": [
"Patch",
"Issue Tracking"
]
}
]
}