CVE-2026-73570
Zimbra Collaboration Suite (ZCS) OS Command Injection Vulnerability
- High 8.9
- Exploited: added to CISA KEV 21 Aug 2026
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.
Key facts
- Published
- 13 Aug 2026
- Last changed
- 24 Aug 2026
- Assigned by
- mitre
- KEV added
- 21 Aug 2026
- KEV fix due
- 24 Aug 2026
- EPSS
- 76.619% likely to be exploited in the next 30 days, higher than 99.551% of CVEs (scores for 15 Nov 2026)
- SSVC (CISA)
- Exploitation: active; Automatable: no; Technical impact: total
Severity scores
Each score is shown as its source gave it. They are not averaged or merged.
- 8.9CVSS 3.1, Highfrom the CNA (mitre)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:L
What to do
- 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.CISA KEV required action
Historical context and remediation
This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.
No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.
Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.
Affected products
| Vendor | Product | Versions |
|---|---|---|
| Zimbra | Collaboration |
|
Timeline
- 13 Aug 2026 Published
- 21 Aug 2026 Added to the CISA KEV catalogue
Weakness
Practice this bug class
HackZoneLabs has a hands-on lab on OS command injection (CWE-78).