CVE-2026-6732: Libxml2: libxml2: denial of service via crafted xsd-validated document

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-04-23 · updated 2026-10-26
Weakness: CWE-843

Description

A flaw was found in libxml2. This vulnerability occurs when the library processes a specially crafted XML Schema Definition (XSD) validated document that includes an internal entity reference. An attacker could exploit this by providing a malicious document, leading to a type confusion error that causes the application to crash. This results in a denial of service (DoS), making the affected system or application unavailable.

Affected products

IBM AIX: from 7.2.5 before 7.2.5.12; from 7.3.2 before 7.3.3.3; 7.3.4 — fixed in 7.2.5.12, 7.3.3.3
IBM VIOS: from 4.1.0 before 4.1.1.30; 4.1.2.0 — fixed in 4.1.1.30
Red Hat Enterprise Linux: 6.0, 7.0, 8.0, 9.0, 10.0
RedHat Hardened Images: all versions
RedHat Jboss Core Services: all versions
Red Hat OpenShift Container Platform 4.18: 4.0
xmlsoft libxml2: from 2.13.0 before 2.15.3 — fixed in 2.15.3

How to fix

Upgrade to a fixed version: IBM AIX 7.2.5.12, 7.3.3.3; IBM VIOS 4.1.1.30; xmlsoft libxml2 2.15.3. Check the vendor advisory for mitigations.

References

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