Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-06-29T13:21:42 libxml2: libxml2: Arbitrary code execution in xmlcatalog utility via buffer overflow 4.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:L CWE-120

libxml2 is vulnerable to multiple stack-based buffer overflows in the xmlcatalog utility when running in --shell mode. The usershell() function processes user input using fixed-size stack buffers without proper bounds checking. By supplying an overly long input line, an attacker can overflow internal buffers (command, arg, and argv) during input parsing. This results in memory corruption within the stack frame. Successful exploitation may cause a crash or potentially allow arbitrary code execution in the context of the xmlcatalog process. This issue has been fixed in the commit c2e233fc. NOTE: The maintainers of this project did not agree that this issue is a vulnerability and considered it a bug.

A flaw was found in libxml2, specifically within the xmlcatalog utility when operating in shell mode. An attacker can exploit multiple stack-based buffer overflows by providing an excessively long input line. This leads to memory corruption, which may cause the application to crash or potentially allow the attacker to execute arbitrary code within the context of the xmlcatalog process.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability. Red Hat Hardened Images 2026-06-30T00:00:00Z RHSA-2026:33840 libxml2-main-2.15.3-0.1.1.hum1 Red Hat Enterprise Linux 10 Fix deferred libxml2 Red Hat Enterprise Linux 6 Fix deferred libxml2 Red Hat Enterprise Linux 7 Fix deferred libxml2 Red Hat Enterprise Linux 8 Fix deferred libxml2 Red Hat Enterprise Linux 8 Fix deferred podman Red Hat Enterprise Linux 9 Fix deferred libxml2 Red Hat OpenShift Container Platform 4 Fix deferred rhcos https://www.cve.org/CVERecord?id=CVE-2026-11979 https://nvd.nist.gov/vuln/detail/CVE-2026-11979 https://cert.pl/en/posts/2026/06/CVE-2026-11979 https://gitlab.gnome.org/GNOME/libxml2/-/commit/c2e233fc1b341685fc99621b2768b503f777a72e