Overview
What is CVE-2026-86138?
In libxml2 before 2.15.4, xmlDictAddQString in dict.c has an integer overflow and resultant heap-based buffer overflow.
Vulnerability intelligence
CVE-2026-86138 and is rated Medium severity with a CVSS score of 6.9. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
In libxml2 before 2.15.4, xmlDictAddQString in dict.c has an integer overflow and resultant heap-based buffer overflow.