Severity: HighAction: PatchExploitation: ExploitedCISA KEV
Unauthenticated command injection on internet-facing mail servers: tracking CVE-2026-73570
Microsoft Threat Intelligence examines CVE-2026-73570 exploitation in Zimbra, including observed attack paths, detection opportunities, and mitigation guidance.
Why it matters
CISA lists this as exploited in the wild. Unpatched Zimbra Collaboration Suite (ZCS) systems are exposed to active attacks now.
Patch
Apply the vendor's security update for Zimbra Collaboration Suite (ZCS).