CVE-2020-8633: Synacor Zimbra Collaboration Suite

Medium severity, CVSS 5.3. EPSS: 1.1% chance of exploitation in the next 30 days.

An issue was discovered in Zimbra Collaboration Suite (ZCS) before 8.8.15 Patch 7. When grantors revoked a shared calendar in Outlook, the calendar stayed mounted and accessible.

Affected products

• Synacor Zimbra Collaboration Suite: before 8.8.15 (fixed in 8.8.15); version 8.8.15 only

Published 2020-02-18. Last modified 2026-06-17.