CVE-2026-6653

Use After Free in libxml2's xmlParseInternalSubset from GNOME libxml2 version 2.9.11 to 2.11.0 allows a remote attacker to cause a denial-of-service via maliciously crafted XML input with improper entity resolution handling.

CVSS v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://bugs.launchpad.net/ubuntu/+source/libxml2/+bug/2141260	Exploit Issue Tracking Third Party Advisory
https://gitlab.gnome.org/GNOME/libxml2/-/work_items/1058	Exploit Issue Tracking Patch

Configurations

Configuration 1 (hide)

cpe:2.3:a:xmlsoft:libxml2:*:*:*:*:*:*:*:*

History

25 Oct 2026, 23:10

Type	Values Removed	Values Added
Summary		(es) Uso después de liberación en xmlParseInternalSubset de libxml2 desde la versión 2.9.11 hasta la 2.11.0 de GNOME libxml2 permite a un atacante remoto causar una denegación de servicio mediante una entrada XML maliciosamente elaborada con un manejo inadecuado de la resolución de entidades.

Information

Published : 2026-06-22 14:17

Updated : 2026-10-25 23:10

NVD link : CVE-2026-6653

Mitre link : CVE-2026-6653

CVE.ORG link : CVE-2026-6653

JSON object : View

Products Affected

xmlsoft

libxml2

CWE

CWE-416

Use After Free

CWE-611

Improper Restriction of XML External Entity Reference

{"id": "CVE-2026-6653", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-6653", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-06-22T15:51:00.508541Z"}}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.8, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 3.9}], "cvssMetricV40": [{"type": "Secondary", "source": "security@ubuntu.com", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 7.0, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "HIGH", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/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", "exploitMaturity": "PROOF_OF_CONCEPT", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "HIGH", "attackRequirements": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "LOW", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "LOW", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "security@ubuntu.com", "affectedData": [{"repo": "https://gitlab.gnome.org/GNOME/libxml2", "vendor": "GNOME", "product": "libxml2", "versions": [{"status": "affected", "version": "2.9.11", "lessThan": "2.11.0", "versionType": "semver"}], "packageName": "libxml2", "defaultStatus": "unaffected"}]}], "published": "2026-06-22T14:17:51.113", "references": [{"url": "https://bugs.launchpad.net/ubuntu/+source/libxml2/+bug/2141260", "tags": ["Exploit", "Issue Tracking", "Third Party Advisory"], "source": "security@ubuntu.com"}, {"url": "https://gitlab.gnome.org/GNOME/libxml2/-/work_items/1058", "tags": ["Exploit", "Issue Tracking", "Patch"], "source": "security@ubuntu.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security@ubuntu.com", "description": [{"lang": "en", "value": "CWE-416"}, {"lang": "en", "value": "CWE-611"}]}], "descriptions": [{"lang": "en", "value": "Use After Free in libxml2's xmlParseInternalSubset from GNOME libxml2 version 2.9.11 to 2.11.0 allows a remote attacker to cause a denial-of-service via maliciously crafted XML input with improper entity resolution handling."}, {"lang": "es", "value": "Uso despu\u00e9s de liberaci\u00f3n en xmlParseInternalSubset de libxml2 desde la versi\u00f3n 2.9.11 hasta la 2.11.0 de GNOME libxml2 permite a un atacante remoto causar una denegaci\u00f3n de servicio mediante una entrada XML maliciosamente elaborada con un manejo inadecuado de la resoluci\u00f3n de entidades."}], "lastModified": "2026-10-25T23:10:00.167", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:xmlsoft:libxml2:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "52D9DF90-B6D6-4520-AB52-DCC1F17711F4", "versionEndIncluding": "2.11.0", "versionStartIncluding": "2.9.11"}], "operator": "OR"}]}], "sourceIdentifier": "security@ubuntu.com"}