CVE-2026-56132: Libexpat Project Libexpat

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

In libexpat before 2.8.2, there is a heap-based buffer overflow in doProlog in xmlparse.c because scaffold backing array reallocation is mishandled when there is data-structure sharing across parsers.

Affected products

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

Published 2026-06-19. Last modified 2026-06-23.