CVE-2026-56407: Libexpat Project Libexpat

Medium severity, CVSS 6.9. EPSS: 0.2% chance of exploitation in the next 30 days.

libexpat before 2.8.2 has an integer overflow in doProlog that is related to storeEntityValue and entity textLen.

Affected products

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

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