CVE-2026-0990: Libxml2: libxml2: denial of service via uncontrolled recursion in xml catalog processing

Severity: medium (CVSS 5.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.0% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-01-15 · updated 2026-09-01
Weakness: CWE-674

Description

A flaw was found in libxml2, an XML parsing library. This uncontrolled recursion vulnerability occurs in the xmlCatalogXMLResolveURI function when an XML catalog contains a delegate URI entry that references itself. A remote attacker could exploit this configuration-dependent issue by providing a specially crafted XML catalog, leading to infinite recursion and call stack exhaustion. This ultimately results in a segmentation fault, causing a Denial of Service (DoS) by crashing affected applications.

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: before 2.15.2 — fixed in 2.15.2

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 2.15.2. Check the vendor advisory for mitigations.

References

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