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CISA KEV digest

CISA KEV 21 Aug 2026: 1 exploited flaw in Synacor

1 vulnerability
Conceptual illustration: An anonymous envelope and glass video-meeting window connected to a protected server. Headline: EMAIL & COLLABORATION.

AI-generated illustration by CyberShitty. Not a photograph or a document from the organisations named.

On 21 August 2026, CISA added 1 actively exploited vulnerability affecting Synacor to its Known Exploited Vulnerabilities catalog. If you run any of these products, patch or mitigate now — exploitation is already happening.

CVE-2026-73570Federal deadline

In this section

Zimbra Collaboration Suite (ZCS) OS Command Injection Vulnerability

Synacor / Zimbra Collaboration Suite (ZCS) / CWE-78

Zimbra Collaboration Suite (ZCS) contains an OS command injection vulnerability which could allow an unauthenticated attacker to send specially crafted SMTP requests that may result in execution of arbitrary operating system commands as the Zimbra user.

Required action: 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.