CVE-2026-73570 (GCVE-0-2026-73570)

Vulnerability from cvelistv5 – Published: 2026-08-13 15:19 – Updated: 2026-08-22 03:55
VLAI CISA ENISA
Summary
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.
Severity
8.9 (High)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:L
SSVC
Exploitation: active Automatable: no Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-13 00:00 UTC
CWE
  • CWE-78 - Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Assigner
References
Impacted products
Vendor Product Version CPE status
Zimbra Collaboration Affected: 0 , < 10.1.20 (custom)
    cpe:2.3:a:zimbra:collaboration:*:*:*:*:*:*:*:*
Create a notification for this product.
CISA
Known Exploited Vulnerability - GCVE BCP-07 Compliant
KEV entry ID: f8846663-2283-4a00-a693-54d43a5f985d

Vulnerability ID: CVE-2026-73570

Status: Confirmed

Status Updated: 2026-08-21 00:00 UTC

Exploited: Yes

Timestamps
First Seen: 2026-08-21
Asserted: 2026-08-21
Scope
Notes: Zimbra Collaboration Suite (ZCS) OS Command Injection Vulnerability | Affected: Synacor / Zimbra Collaboration Suite (ZCS) | 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. | Due date: 2026-08-24 | Known ransomware campaign use (KEV): Unknown | Notes (KEV): 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
Evidence

Type: Vendor Report

Signal: Successful Exploitation

Confidence: 80%

Source: cisa-kev

Details
Cwes CWE-78
Feed CISA Known Exploited Vulnerabilities Catalog
Product Zimbra Collaboration Suite (ZCS)
Due Date 2026-08-24
Date Added 2026-08-21
Vendorproject Synacor
Vulnerabilityname Zimbra Collaboration Suite (ZCS) OS Command Injection Vulnerability
Knownransomwarecampaignuse Unknown
References
Created: 2026-08-21 17:00 UTC | Updated: 2026-08-21 17:00 UTC
ENISA
Known Exploited Vulnerability - GCVE BCP-07 Compliant
KEV entry ID: c0bf679d-88c4-4a63-9674-a7bec42990c9

Vulnerability ID: CVE-2026-73570

Status: Confirmed

Status Updated: 2026-08-18 00:00 UTC

Exploited: Yes

Timestamps
First Seen: 2026-08-18
Asserted: 2026-08-18
Scope
Notes: Affected: Zimbra / Collaboration | Description: Improper sanitization of untrusted input during SNMP notification processing. Exploitation waves since the beginning of August 2026. | Patched since: 2026/07/20 | Exploitation type: unknown | CWEs: CWE-78 | Origin source: CERT.PL | Notes: https://wiki.zimbra.com/wiki/Zimbra_Releases/10.1.20
Evidence

Type: Csirt Report

Signal: Successful Exploitation

Confidence: 75%

Source: enisa-cnw-kev

Details
Cwes CWE-78
Euvd EUVD-2026-58069
Notes https://wiki.zimbra.com/wiki/Zimbra_Releases/10.1.20
Catalog ENISA / EU CSIRTs Network (CNW) KEV JSON
Product Collaboration
Datereported 2026/08/18
Originsource CERT.PL
Patchedsince 2026/07/20
Vendorproject Zimbra
Exploitationtype unknown
Vulnerabilityname
Threatactorsexploiting
References
Created: 2026-08-19 17:44 UTC | Updated: 2026-08-19 17:44 UTC
Show details on NVD website
To clipboard 

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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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