CVE-2026-86138

CVE-2026-86138

In libxml2 before 2.15.4, xmlDictAddQString in dict.c has an integer overflow and resultant heap-based buffer overflow.

Vulnerability class: Integer Overflow

CVSS v3 metric

CVSS v3 base score 6.9 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:L.

Weakness classification (CWE)

CWE-190 — Integer Overflow or Wraparound

References

Frequently asked questions

What is CVE-2026-86138?: CVE-2026-86138 is a medium-severity vulnerability, classified under Integer Overflow or Wraparound. CVSS score: 6.9/10. Published 2026-09-05.
How severe is CVE-2026-86138?: Medium severity. CVSS v3 base score is 6.9 out of 10.