Actively exploited · Published Aug 13, 2026 · Assigned by mitre

CVE-2026-73570

High 8.9 Exploited

In plain English

A high-severity OS command injection in Collaboration from Zimbra. Attackers are actively exploiting it in the wild (listed by CISA on August 21, 2026). The chance it is exploited in the next 30 days is estimated at 71.7% (higher than 99.4% of all known vulnerabilities). Ready-made attack tooling exists: Nuclei, public proof-of-concept code. 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.

Severity (CVSS 3.1)8.9High
Exploit odds (30 days)71.7%top 0.6% of all CVEs
Exploited in the wildYesCISA KEV since Aug 21, 2026
Attack tooling2Nuclei, Public PoC

CISA guidance

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.

Federal agencies must remediate by Aug 24, 2026.

Official description

A remote code execution vulnerability exists in Zimbra Collaboration (ZCS) before 10.1.20 when the optional zimbra-snmp package is installed and SNMP notifications are enabled. Due to improper sanitization of untrusted input during SNMP notification processing, an unauthenticated attacker can send specially crafted SMTP requests that may result in execution of arbitrary operating system commands as the Zimbra user.

Affected products (as reported)

VendorProductVersions
Zimbra Collaboration 0 – before 10.1.20

Weakness: CWE-78 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:L

References