Patchfirst
CVE-2026-73570 KEVPublic exploit High · 8.9 EPSS 71.7%

Zimbra Collaboration Suite (ZCS) OS Command Injection Vulnerability

Synacor · Zimbra Collaboration Suite (ZCS)

Summary

Zimbra Collaboration Suite (ZCS) before 10.1.20 contains an OS command injection flaw in SNMP notification processing, which arises when the optional zimbra-snmp package is installed and SNMP notifications are enabled. An unauthenticated remote attacker who can send specially crafted SMTP requests to the server may be able to execute arbitrary operating system commands as the Zimbra user, though the attack requires a high-complexity condition and the specific SNMP configuration described above.

Official description · NVD

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.

Breakdown
76.1 / 100
Exploited
Yes, in CISA KEV
Reports
0
Tactics
2/15

How an attack unfolds

Based on mappings. Select a step to see the evidence.
  1. How attackers get in

  2. What they do

First seen exploited 4 days after disclosure. Public exploit code (PoC-in-GitHub) appeared 8 days after disclosure.

  1. Disclosedday 0
  2. First seen exploitedVulnCheck KEV evidence+4 days
  3. EU database marks exploited+5 days
  4. Added to CISA KEVPublic exploit codePoC-in-GitHub+8 days

CISA KEV listing is when exploitation was confirmed, not necessarily the first attack.

techniques

2 , grouped by in kill-chain order, 2 cited passages 2

Initial AccessTA0001

Exploit Public-Facing Application T1190 Medium
AI mapping from the description · how it is exploited

Unauthenticated network requests exploit a public-facing mail service

an unauthenticated attacker can send specially crafted SMTP requests
From the official description (NVD) Original (opens in a new tab) ↗

ExecutionTA0002

Command and Scripting Interpreter T1059 Medium
AI mapping from the description · primary impact

Arbitrary OS command execution is the direct impact

may result in execution of arbitrary operating system commands
From the official description (NVD) Original (opens in a new tab) ↗

Detection

0 rules for this CVE · 244 general rules for its techniques

Rules for this CVE

0 that reference CVE-2026-73570 directly.

CVE-specific rules are not available in this build. Search SigmaHQ ↗

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What security researchers reported

Not named in any threat report yet

References

4 links, grouped by NVD tag
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