CVEs / CVE-2026-73570
CVE-2026-73570: Zimbra Collaboration Suite (ZCS) OS Command Injection Vulnerability
- Known exploited in the CISA KEV catalog since 21 Aug 2026
- high 8.9 CVSS 3.1 (from the CNA)
- EPSS 71.6% chance of exploitation in the next 30 days, higher than 99% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
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.
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 and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| Zimbra Collaboration | before 10.1.20 | 10.1.20 |
Exploitation
| In CISA KEV since | 21 Aug 2026 |
|---|---|
| Due date for US federal agencies | 24 Aug 2026 |
| Used in ransomware campaigns | Unknown |
| 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. |
Severity
| CVSS 3.1 | 8.9 highCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:LScored by the CNA ([email protected]) |
|---|---|
| Weakness | CWE-78 |
References
- CVE-2026-73570 on NVD
- CVE-2026-73570 in the CISA KEV catalog
- https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories (cited by CISA)
- https://blog.zimbra.com/2026/07/patch-release-update-zimbra-10-1-20/ (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk (cited by CISA)
- CVE-2026-73570 on OSV
- 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
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.