CVE-2022-27924: Synacor Zimbra Collaboration Suite (ZCS) Command Injection Vulnerability

High severity, CVSS 7.5. Actively exploited: in CISA KEV since 2022-08-04. EPSS: 93.9% chance of exploitation in the next 30 days.

Zimbra Collaboration (aka ZCS) 8.8.15 and 9.0 allows an unauthenticated attacker to inject arbitrary memcache commands into a targeted instance. These memcache commands becomes unescaped, causing an overwrite of arbitrary cached entries.

Affected products

• Synacor Zimbra Collaboration Suite: version 8.8.15 only; version 9.0.0 only

Published 2022-04-21. Last modified 2026-10-02.