Zimbra Collaboration Suite (ZCS) OS Command Injection Vulnerability
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.
MANARTECH SECURITY ALERT
Zimbra Collaboration Suite (ZCS) OS Command Injection Vulnerability
CVE Numbers
CVE-2026-73570
Affected Product
Zimbra Collaboration Suite (ZCS) — Synacor
Threat Description
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.
Severity Scale
CRITICALHIGHMEDIUMLOW
Severity
HIGH
Affected Versions
To be reviewed
Recommended Mitigation
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.
Reference Links
https://wiki.zimbra.com/wiki/Security_Center
https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories
https://moje.cert.pl/komunikaty/2026/145/aktywnie-wykorzystywana-podatnosc-w-zimbra-collaboration-suite/
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-73570
https://nvd.nist.gov/vuln/detail/CVE-2026-73570
