Heap-based buffer overflow in Libxml2 - CVE-2026-86142
Published: September 8, 2026
Vulnerability identifier: #VU147360
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-86142
CWE-ID: CWE-122
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to a heap-based buffer overflow in xmlXPtrEvalXPtrPart when processing XPointer input. A remote attacker can provide crafted XPointer input to cause a denial of service.
The overflow is caused by XPointer length saturation in xmlXPtrEval.
Affected software
Libxml2
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for ARM 64
libxml2 (Red Hat package)
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for ARM 64
libxml2 (Red Hat package)
How to mitigate CVE-2026-86142
Install security update from vendor's website.
Libxml2 - update to 2.15.4
libxml2 (Red Hat package) - update to 2.9.7-21.el8_10.10
libxml2 (Red Hat package) - update to 2.9.7-21.el8_10.10