RHSA-2026:93463: Important: libxml2 security, bug fix, and enhancement update
The libxml2 library is a development toolbox providing the implementation of various XML standards.Security Fix(es): libxml2: mingw-libxml2: libxml2: Denial of Service via crafted XML input due to use-after-free (CVE-2026-6653) libxml2: libxml2: Arbitrary code execution in xmlcatalog utility via buffer overflow (CVE-2026-11979) libxml2: libxml2: Arbitrary code execution via heap-based buffer overflow (CVE-2026-86138) libxml2: libxml2: Data integrity issues due to integer overflow in write callbacks (CVE-2026-86143) libxml2: libxml2: Arbitrary code execution via stack-based buffer overflow in xmlSnprintfElements (CVE-2026-86140) libxml2: libxml2: Heap-based buffer overflow in xmlXPtrEval due to xpointer length saturation (CVE-2026-86142) libxml2: libxml2: Information disclosure, SSRF, or denial of service due to improper parseFlags propagation. (CVE-2026-86144) libxml2: double-free/UAF in libxml2 Python bindings (CVE-2026-74860) Bug Fix(es) and Enhancement(s): libxml2: CVE-2025-9714 fix (RHEL-131764) backported wrong upstream commit ? dyn:map recursion still crashes (JIRA:RHEL-277427) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
redhat/libxml2to a version that resolves this vulnerability.Fixed in 2.9.7-16.el8_8.24 - Upgrade
Upgrade
redhat/libxml2-debuginfoto a version that resolves this vulnerability.Fixed in 2.9.7-16.el8_8.24 - Upgrade
Upgrade
redhat/libxml2-debugsourceto a version that resolves this vulnerability.Fixed in 2.9.7-16.el8_8.24 - Upgrade
Upgrade
redhat/libxml2-develto a version that resolves this vulnerability.Fixed in 2.9.7-16.el8_8.24 - Upgrade
Upgrade
redhat/python3-libxml2to a version that resolves this vulnerability.Fixed in 2.9.7-16.el8_8.24 - Upgrade
Upgrade
redhat/python3-libxml2-debuginfoto a version that resolves this vulnerability.Fixed in 2.9.7-16.el8_8.24
Event History
Frequently Asked Questions
Which components and use cases are implicated by this update?
The advisory identifies issues in the core libxml2 library, the xmlcatalog utility, and the libxml2 Python bindings. XML parsing, XPointer evaluation, catalog handling, write callbacks, and code paths that propagate parse flags are specifically mentioned.
What attacker-controlled input or access appears relevant to exploitation?
Several issues are described as involving crafted XML input, while others involve XML parsing or evaluation paths. The xmlcatalog issue is specifically associated with the xmlcatalog utility, and the Python binding issue affects applications using libxml2's Python bindings.
What impact types are addressed?
The listed impacts include denial of service, arbitrary code execution, data-integrity issues, information disclosure, and server-side request forgery. Multiple memory-safety flaws are identified, including use-after-free, double-free, and heap- and stack-based buffer overflows.
How can I determine whether an application may be exposed?
Review applications that process untrusted XML with libxml2, invoke xmlcatalog, use XPointer functionality, or rely on libxml2 Python bindings. Also review parsing configurations where parse flags affect external resource handling, since one issue can lead to information disclosure, SSRF, or denial of service through improper parse-flag propagation.