CVE-2026-56411: Libexpat Project Libexpat

Medium severity, CVSS 6.9. EPSS: 0.1% chance of exploitation in the next 30 days.

xmlwf in libexpat before 2.8.2 has an integer overflow in endDoctypeDecl via NOTATION declarations.

Affected products

• Libexpat Project Libexpat: before 2.8.2 (fixed in 2.8.2)

Published 2026-06-21. Last modified 2026-06-23.