CVE-2026-73570

HIGH

8.9

CVSS Score

Published: August 13, 2026 at 03:19 PM UTC

Updated: August 24, 2026 at 01:19 PM UTC

4 products affected across 2 vendorsCollaborationZimbra Collaboration SuiteCollaboration

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Severity

HIGH8.9

Exploitation

CISA KEV

Exploit prediction

EPSS 72%

SSVC

Active

Actively Exploited

CISA Known Exploited Vulnerabilities (KEV) Catalog

EPSS Score71.7%

EPSS (Exploit Prediction Scoring System) estimates a 71.7% chance this CVE is exploited in the wild within the next 30 days — higher than 99% of all CVEs. It complements CVSS: a high EPSS on a mid-severity CVE can still be urgent.

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.

Ransomware Use

Unknown

Added to KEV

Aug 21, 2026

Remediation Due

Aug 24, 2026

67 days overdue

Notes

https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories

https://blog.zimbra.com/2026/07/patch-release-update-zimbra-10-1-20/

BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk

Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk

https://nvd.nist.gov/vuln/detail/CVE-2026-73570

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.