CVE-2016-6290: PHP

Critical severity, CVSS 9.8. EPSS: 5.5% chance of exploitation in the next 30 days.

ext/session/session.c in PHP before 5.5.38, 5.6.x before 5.6.24, and 7.x before 7.0.9 does not properly maintain a certain hash data structure, which allows remote attackers to cause a denial of service (use-after-free) or possibly have unspecified other impact via vectors related to session deserialization.

Affected products

• PHP PHP: up to and including 5.5.37; version 5.6.0 only; version 5.6.1 only; version 5.6.2 only; version 5.6.3 only; version 5.6.4 only; …

Published 2016-07-25. Last modified 2026-06-17.