Actively exploited in the wild
Zimbra Collaboration Suite (ZCS) OS Command Injection Vulnerability
Synacor - Zimbra Collaboration Suite (ZCS) · Listed in the CISA KEV since 2026-08-21. This indicates confirmed attacks in production environments.
Required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
CVE-2026-73570
HighCVSS 8.9KEVExploitation Probability (EPSS)
Low risk43th percentile - higher than 43% of all known CVEs
Summary
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.
Risk Assessment
Risk of full compromise of the Zimbra server by an unauthenticated attacker, potentially leading to confidentiality, integrity, and availability breaches.
Recommendation
Update Zimbra Collaboration to version 10.1.20 or later, and if not required, disable the zimbra-snmp package and SNMP notifications.
Original NVD description (English source)
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.