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.
Timeline
- 2026-08-13Published to the U.S. National Vulnerability Database (NVD)
- 2026-08-21First covered in a defend.network daily briefing
- 2026-08-21Added to the CISA Known Exploited Vulnerabilities (KEV) catalog
- 2026-08-24CISA federal remediation deadline (BOD 22-01)
- 2026-08-24NVD record last updated
CISA Known Exploited Vulnerability
Zimbra Collaboration Suite (ZCS) OS Command Injection Vulnerability
Affected product
Synacor Zimbra Collaboration Suite (ZCS)
Remediation Steps
- Apply the vendor security update for Synacor Zimbra Collaboration Suite as a priority.
- Restrict network exposure of the affected service to trusted sources until patched.
- Review logs and detections for indicators of exploitation.
- Confirm fixed versions against the official vendor advisory before deploying.
References
- https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories
- https://moje.cert.pl/komunikaty/2026/145/aktywnie-wykorzystywana-podatnosc-w-zimbra-collaboration-suite/
- https://wiki.zimbra.com/wiki/Security_Center
- https://nvd.nist.gov/vuln/detail/CVE-2026-73570
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog
Referenced in our briefings & reports
- Vulnerability Priority Report – Week 4 of September 2026 (September 28 – October 4)
- Vulnerability Priority Report – Week 2 of September 2026 (September 14 – 20)
- Vulnerability Priority Report – Week 1 of September 2026 (September 7 – 13)
- Vulnerability Priority Report – Week 5 of August 2026 (August 31 – September 6)
- Vulnerability Priority Report – Week 4 of August 2026 (August 24 – 30)
- Vulnerability Priority Report – Week 3 of August 2026 (August 17 – 23)
- Cisco SD-WAN, Zimbra, Zammad under attack; active exploitation confirmed (2026-10-01)
- Keycloak authentication bypass, Microsoft active exploit, WordlistLoader/SynkLoader malware (2026-08-25)
- Microsoft patches 398 flaws; Zimbra exploitation deadline looms; Android cars compromised (2026-08-24)
- Android vehicles, AWS keys, Snowflake extortionist: Active threats escalate (2026-08-23)
- Rust supply-chain attack, Microsoft patches 398 flaws, Siemens PLCs targeted by AI-generated exploits (2026-08-21)
Browse all tracked CVEs in the defend.network CVE database →
🤖 This CVE page is generated by defend.network from NVD, CISA KEV, EPSS, and our verified daily briefings. Severity and exploitation data come from official sources; always verify remediation steps against the official vendor advisory before acting in production.