CVE-2018-6340: Facebook Hhvm

High severity, CVSS 8.1. EPSS: 1.4% chance of exploitation in the next 30 days.

The Memcache::getextendedstats function can be used to trigger an out-of-bounds read. Exploiting this issue requires control over memcached server hostnames and/or ports. This affects all supported versions of HHVM (3.30 and 3.27.4 and below).

Affected products

• Facebook Hhvm: up to and including 3.27.4; version 3.30 only

Published 2018-12-31. Last modified 2026-06-17.