CVE-2020-1916: Facebook Hhvm

Critical severity, CVSS 9.8. EPSS: 1.4% chance of exploitation in the next 30 days.

An incorrect size calculation in ldap_escape may lead to an integer overflow when overly long input is passed in, resulting in an out-of-bounds write. This issue affects HHVM prior to 4.56.2, all versions between 4.57.0 and 4.78.0, 4.79.0, 4.80.0, 4.81.0, 4.82.0, 4.83.0.

Affected products

• Facebook Hhvm: before 4.56.2 (fixed in 4.56.2); from 4.57.0, before 4.78.1 (fixed in 4.78.1); version 4.79.0 only; version 4.80.0 only; version 4.81.0 only; version 4.82.0 only; …

Published 2021-03-10. Last modified 2026-06-17.