CVE-2026-86137: Xmlsoft LIBXML2

Medium severity, CVSS 6.1. EPSS: 0.2% chance of exploitation in the next 30 days.

In libxml2 before 2.15.4, xmlFAParsePosCharGroup has an out-of-bounds read, aka an out-of-bounds read in the NXT macro in xmlregexp.

Affected products

• Xmlsoft LIBXML2: before 2.15.4 (fixed in 2.15.4)

Published 2026-09-05. Last modified 2026-09-15.