CISA Adds Zimbra Collaboration Suite CVE-2026-73570 to KEV Catalog After Confirmed Exploitation
US authorities have warned organizations about active exploitation of a vulnerability in the collaboration platform Zimbra Collaboration Suite (ZCS). The CISA added the flaw to its Known Exploited Vulnerabilities catalog on August 21, 2026.
The vulnerability, tracked as CVE-2026-73570, is an OS command injection issue located in the SNMP monitoring component. When SNMP notifications are enabled, a specially crafted SMTP request can allow an attacker to execute arbitrary operating system commands without authentication, using the privileges of a Zimbra user.
MITRE assigned the flaw a CVSS v3.1 base score of 8.9, rating it High severity. CISA has directed US federal agencies to implement mitigations by August 24, 2026. All organizations running the affected product should treat the issue as actively exploited and apply available patches or workarounds immediately.
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