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Known Exploited Vulnerability
8.9
HIGH CVSS 3.1
CVE-2026-73570
Zimbra Collaboration Suite (ZCS) OS Command Injection Vulnerability - [Actively Exploited]
Overview
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.

Details
INFO

Published Date :

Aug. 13, 2026, 4:19 p.m.

Last Modified :

Aug. 24, 2026, 1:19 p.m.

Remotely Exploit :

Yes !

Source :

[email protected]
CISA Notification
CISA KEV (Known Exploited Vulnerabilities)

For the benefit of the cybersecurity community and network defenders—and to help every organization better manage vulnerabilities and keep pace with threat activity—CISA maintains the authoritative source of vulnerabilities that have been exploited in the wild.

Description :

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.

Known Ransomware Campaign Use:

Unknown

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

Impact
Affected Products

The following products are affected by CVE-2026-73570 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Zimbra collaboration
1 Synacor zimbra_collaboration_suite
: Total Affected Vendor : 2 | Products : 2
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 HIGH 8254265b-2729-46b6-b9e3-3dfca2d5bfca
CVSS 3.1 HIGH [email protected]
CVSS 3.1 HIGH MITRE-CVE
Solution
Update Zimbra Collaboration to version 10.1.20 or later to fix the remote code execution vulnerability.
  • Update Zimbra Collaboration to version 10.1.20 or later.
  • Ensure the zimbra-snmp package is not installed.
  • Disable SNMP notifications if the package is installed.
  • Sanitize all user input for SNMP notification processing.
References
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-73570.

URL Resource
https://wiki.zimbra.com/wiki/Security_Center Release Notes
https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories Vendor Advisory
https://moje.cert.pl/komunikaty/2026/145/aktywnie-wykorzystywana-podatnosc-w-zimbra-collaboration-suite/ Third Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-73570 US Government Resource
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-73570 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-73570 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-73570 vulnerability anywhere in the article.

  • TheCyberThrone
CISA adds TrueConf and Zimbra and Oracle WebLogic to KEV

August 25, 2026CISA has added multiple vulnerabilities affecting TrueConf Server, Zimbra Collaboration Suite and Oracle HTTP Server/WebLogic Server Proxy Plug-in to its Known Exploited Vulnerabilities ... Read more

Published Date: Aug 25, 2026 (1 week, 3 days ago)
  • security.nl
Honderden Zimbra-mailservers gehackt via lek, duizenden nog ongepatcht

Aanvallers hebben de afgelopen weken honderden Zimbra-mailservers gehackt, waarbij gebruikt werd gemaakt van een kwetsbaarheid waarvoor sinds 20 juli een beveiligingsupdate beschikbaar is. Dat meldt T ... Read more

Published Date: Aug 24, 2026 (1 week, 5 days ago)
  • The Hacker News
Attackers Exploit Zimbra SNMP Flaw for Unauthenticated Remote Code Execution

A now-patched security flaw impacting Zimbra Collaboration (ZCS) has come under active exploitation in the wild, according to the Polish Computer Emergency Response Team (CERT Polska). The vulnerabili ... Read more

Published Date: Aug 20, 2026 (2 weeks, 2 days ago)
  • security.nl
Poolse overheid waarschuwt voor misbruik van lek in Zimbra-mailservers

De Poolse overheid waarschuwt voor misbruik van een beveiligingslek in Zimbra waardoor ongeauthenticeerde aanvallers commando's en code op mailservers kunnen uitvoeren. Er is daarbij geen enkele inter ... Read more

Published Date: Aug 20, 2026 (2 weeks, 2 days ago)

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-73570 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Aug. 24, 2026

    Action Type Old Value New Value
    Changed SSVC {'id': 'CVE-2026-73570', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-13T00:00:00+00:00'} {'id': 'CVE-2026-73570', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-22T03:55:17.911879Z'}
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Aug. 22, 2026

    Action Type Old Value New Value
    Changed SSVC {'id': 'CVE-2026-73570', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-21T17:18:39.211103Z'} {'id': 'CVE-2026-73570', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-13T00:00:00+00:00'}
  • Initial Analysis by [email protected]

    Aug. 21, 2026

    Action Type Old Value New Value
    Added CPE Configuration OR *cpe:2.3:a:synacor:zimbra_collaboration_suite:*:*:*:*:*:*:*:* versions up to (excluding) 10.1.20
    Added Reference Type MITRE: https://wiki.zimbra.com/wiki/Security_Center Types: Release Notes
    Added Reference Type MITRE: https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories Types: Vendor Advisory
    Added Reference Type CISA-ADP: https://moje.cert.pl/komunikaty/2026/145/aktywnie-wykorzystywana-podatnosc-w-zimbra-collaboration-suite/ Types: Third Party Advisory
    Added Reference Type CISA-ADP: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-73570 Types: US Government Resource
  • CVE CISA KEV Update by 9119a7d8-5eab-497f-8521-727c672e3725

    Aug. 21, 2026

    Action Type Old Value New Value
    Added Date Added 2026-08-21
    Added Due Date 2026-08-21
    Added Required Action 2026-08-21
    Added Vulnerability Name 2026-08-21
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Aug. 21, 2026

    Action Type Old Value New Value
    Added Reference https://moje.cert.pl/komunikaty/2026/145/aktywnie-wykorzystywana-podatnosc-w-zimbra-collaboration-suite/
    Added Reference https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-73570
    Changed SSVC {'id': 'CVE-2026-73570', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-13T00:00:00+00:00'} {'id': 'CVE-2026-73570', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'active'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-21T17:18:39.211103Z'}
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Aug. 14, 2026

    Action Type Old Value New Value
    Changed SSVC {'id': 'CVE-2026-73570', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-13T15:52:20.087181Z'} {'id': 'CVE-2026-73570', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-13T00:00:00+00:00'}
  • New CVE Received by [email protected]

    Aug. 13, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'Zimbra', 'product': 'Collaboration', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '10.1.20', 'versionType': 'custom'}], 'defaultStatus': 'unaffected'}]
    Added 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.
    Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:L
    Added CWE CWE-78
    Added Reference https://wiki.zimbra.com/wiki/Security_Center
    Added Reference https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Aug. 13, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-73570', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-13T15:52:20.087181Z'}
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CVSS
Vulnerability Scoring Details
Base CVSS Score: 8.9
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact