CVE-2020-7796
Synacor Zimbra Collaboration Suite (ZCS) Server-Side Request Forgery Vulnerability
Synacor Zimbra Collaboration Suite
Zimbra Collaboration Suite (ZCS) before 8.8.15 Patch 7 allows SSRF when WebEx zimlet is installed and zimlet JSP is enabled.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 17 February 2026. US federal agencies were required to remediate it by 10 March 2026.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 93.6%, which is higher than 99.8% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Frequently asked questions
Is CVE-2020-7796 being exploited by ransomware groups?
No ransomware group in this database is currently recorded as exploiting CVE-2020-7796.
What does CVE-2020-7796 affect?
CVE-2020-7796 affects Synacor Zimbra Collaboration Suite. Zimbra Collaboration Suite (ZCS) before 8.8.15 Patch 7 allows SSRF when WebEx zimlet is installed and zimlet JSP is enabled.
How severe is CVE-2020-7796?
CVE-2020-7796 is rated CRITICAL with a CVSS base score of 9.8. EPSS puts the probability of exploitation in the next 30 days at 93.6%, higher than 99.8% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 10 March 2026.
How should organisations respond to CVE-2020-7796?
Apply the vendor patch for Synacor Zimbra Collaboration Suite as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.