CVE-2026-56412

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.

CVSS v3 4.9 MEDIUM

4.9^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.4 / Impact : 3.4

Attack Vector LOCAL

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
https://github.com/libexpat/libexpat/pull/1278	Patch Issue Tracking

Configurations

Configuration 1 (hide)

cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-06-21 17:16

Updated : 2026-06-23 15:31

NVD link : CVE-2026-56412

Mitre link : CVE-2026-56412

CVE.ORG link : CVE-2026-56412

JSON object : View

Products Affected

libexpat_project

libexpat

CWE

CWE-416

Use After Free

{"id": "CVE-2026-56412", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-56412", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-06-22T16:30:58.502417Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "cve@mitre.org", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 4.9, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "LOW", "privilegesRequired": "NONE", "confidentialityImpact": "LOW"}, "impactScore": 3.4, "exploitabilityScore": 1.4}, {"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.9, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "LOW", "privilegesRequired": "NONE", "confidentialityImpact": "LOW"}, "impactScore": 3.4, "exploitabilityScore": 2.5}]}, "affected": [{"source": "cve@mitre.org", "affectedData": [{"vendor": "libexpat project", "product": "libexpat", "versions": [{"status": "affected", "version": "0", "lessThan": "2.8.2", "versionType": "semver"}], "defaultStatus": "unaffected"}]}], "published": "2026-06-21T17:16:44.657", "references": [{"url": "https://github.com/libexpat/libexpat/pull/1278", "tags": ["Patch", "Issue Tracking"], "source": "cve@mitre.org"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "cve@mitre.org", "description": [{"lang": "en", "value": "CWE-416"}]}], "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."}], "lastModified": "2026-06-23T15:31:30.853", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:libexpat_project:libexpat:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E3A57811-3797-4D35-A4AC-E1AB3CE6F1F3", "versionEndExcluding": "2.8.2"}], "operator": "OR"}]}], "sourceIdentifier": "cve@mitre.org"}