At least 274 internet-facing Zimbra instances have been compromised by unknown attackers via CVE-2026-73570, the Shadowserver Foundation shared on Monday. About CVE-2026-73570 Zimbra Collaboration Suite (ZCS) is a communication and collaboration platform popular with organizations that need to have control over their data or can’t afford a pricy alternative service like Microsoft 365 or Google Workspace.

Source: Help Net Security