Hackers breached over 270 Zimbra servers in ongoing attacks

CISA orders agencies to fix exploited Zimbra vulnerability

The collaboration software’s developer took almost a full month to patch the flaw after disclosing it.

Hackers breached over 270 Zimbra servers in ongoing attacks

Threat actors have already compromised over 270 Zimbra instances in remote code execution attacks targeting a high-severity Zimbra Collaboration Suite (ZCS) vulnerability. [...]

Unpatched Zimbra servers are falling to CVE-2026-73570 attacks

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. CVE-2026-73570 is a code injection flaw S…