What is CVE-2026-56409?

CVE-2026-56409 is a medium-severity vulnerability in Libexpat Project, classified under Integer Overflow or Wraparound. CVSS score: 6.5/10. Published 2026-06-21.

How severe is CVE-2026-56409?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Integer overflow in Libexpat Project

CVE-2026-56409

xmlwf in libexpat before 2.8.2 has an integer overflow for the output filename when -d outputDir is used.

Vulnerability class: Integer Overflow

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:L.

Affected products

Libexpat Project — versions 0

Weakness classification (CWE)

CWE-190 — Integer Overflow or Wraparound

References

cve@mitre.org

Frequently asked questions

What is CVE-2026-56409?: CVE-2026-56409 is a medium-severity vulnerability in Libexpat Project, classified under Integer Overflow or Wraparound. CVSS score: 6.5/10. Published 2026-06-21.
How severe is CVE-2026-56409?: Medium severity. CVSS v3 base score is 6.5 out of 10.