CVE-2016-4817: Dena h2o

High severity, CVSS 7.5. EPSS: 4.4% chance of exploitation in the next 30 days.

lib/http2/connection.c in H2O before 1.7.3 and 2.x before 2.0.0-beta5 mishandles HTTP/2 disconnection, which allows remote attackers to cause a denial of service (use-after-free and application crash) or possibly execute arbitrary code via a crafted packet.

Affected products

• Dena h2o: up to and including 1.7.2; up to and including 2.0.0

Published 2016-06-19. Last modified 2026-06-17.