CVE-2026-73570: Zimbra Collaboration Suite (ZCS) OS Command Injection Vulnerability

High severity, CVSS 8.9. Actively exploited: in CISA KEV since 2026-08-21. EPSS: 71.7% chance of exploitation in the next 30 days.

A remote code execution vulnerability exists in Zimbra Collaboration (ZCS) before 10.1.20 when the optional zimbra-snmp package is installed and SNMP notifications are enabled. Due to improper sanitization of untrusted input during SNMP notification processing, an unauthenticated attacker can send specially crafted SMTP requests that may result in execution of arbitrary operating system commands as the Zimbra user.

Affected products

• Synacor Zimbra Collaboration Suite: before 10.1.20 (fixed in 10.1.20)

Published 2026-08-13. Last modified 2026-08-24.