Uncontrolled Recursion in Libxml2 - CVE-2026-0990

Vulnerability identifier: #VU122088

CSH Severity: Medium

CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green

CVE-ID: CVE-2026-0990

CWE-ID: CWE-674

Exploitation vector: Remote access

Exploit availability: No public exploit available

Affected software:
Libxml2
SUSE Linux Enterprise Server 12 SP5 LTSS Extended
SUSE Linux Enterprise Server for SAP Applications 12
SUSE Linux Enterprise Server 12
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Real Time 15
SUSE Linux Enterprise Desktop 15
SUSE Linux Enterprise Micro
SUSE Linux Enterprise Micro for Rancher
Ubuntu
Python 3 Module
Basesystem Module
openSUSE Leap
openEuler
Anolis OS
LANTIME Operating System Firmware (LTOS)
libxml2 (Ubuntu package)
libxml2-2-32bit
libxml2-doc
libxml2-devel
libxml2-2-debuginfo-32bit
libxml2-2
libxml2-debugsource
libxml2-tools
python-libxml2-debuginfo
python-libxml2-debugsource
libxml2-2-debuginfo
libxml2-tools-debuginfo
python-libxml2
python-libxml2-python-debugsource
python3-libxml2-python
python3-libxml2-python-debuginfo
libxml2-help
python3-libxml2
libxml2-debuginfo
libxml2
libxml2-2-64bit-debuginfo
python311-libxml2-debuginfo
python311-libxml2
python3-libxml2-debuginfo
libxml2-2-32bit-debuginfo
libxml2-devel-32bit
libxml2-python-debugsource
libxml2-devel-64bit
libxml2-2-64bit
libxml2-static

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to an uncontrolled recursion in the xmlCatalogXMLResolveURI function when an XML catalog contains a delegate URI entry that references itself. A remote attacker can pass specially crafted input to the application and perform a denial of service attack.

Cybersecurity Help is currently unaware of any official solution to address this vulnerability.

• https://access.redhat.com/security/cve/CVE-2026-0990
• https://bugzilla.redhat.com/show_bug.cgi?id=2429959