How severe is CVE-2026-73570?

CVE-2026-73570 has a CVSS 3.x base score of 8.9, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability low.

Is CVE-2026-73570 being actively exploited?

Yes. CVE-2026-73570 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2026-08-21, which means active exploitation has been confirmed. It should be prioritised for remediation.

What products are affected by CVE-2026-73570?

CVE-2026-73570 affects Synacor Zimbra Collaboration Suite. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-73570?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.

When was CVE-2026-73570 published?

CVE-2026-73570 was published on 2026-08-13 and last updated on 2026-08-22.

CVE-2026-73570

CVE-2026-73570 is a high-severity vulnerability in Synacor Zimbra Collaboration Suite with a CVSS 3.x base score of 8.9. It is listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, confirming it has been exploited in the wild (added 2026-08-21). The underlying weakness is classified as CWE-78.

Key facts

Severity: High (CVSS 3.x base score 8.9)
EPSS exploit prediction: 1% (61st percentile)
Actively exploited: Yes — listed in CISA KEV (added 2026-08-21)
Weakness: CWE-78
Affected product: Synacor Zimbra Collaboration Suite
Published: 2026-08-13
Last modified: 2026-08-22

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.

Frequently asked questions

What is CVE-2026-73570?: 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.
How severe is CVE-2026-73570?: CVE-2026-73570 has a CVSS 3.x base score of 8.9, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability low.
Is CVE-2026-73570 being actively exploited?: Yes. CVE-2026-73570 is on CISA's Known Exploited Vulnerabilities (KEV) catalog, added on 2026-08-21, which means active exploitation has been confirmed. It should be prioritised for remediation.
What products are affected by CVE-2026-73570?: CVE-2026-73570 affects Synacor Zimbra Collaboration Suite. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-73570?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Because this CVE is known to be actively exploited, treat remediation as urgent — CISA KEV typically sets a short remediation deadline.
When was CVE-2026-73570 published?: CVE-2026-73570 was published on 2026-08-13 and last updated on 2026-08-22.

References

Affected products (1)

cpe:2.3:a:synacor:zimbra_collaboration_suite:*:*:*:*:*:*:*:*

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