What’s Vulnerable › Vulnerabilities

CVE-2020-8633

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-02-18 · updated 2026-06-17
• Weakness: CWE-281

Description

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

• Zimbra Collaboration: before 8.8.15; 8.8.15, 8.8.15-p1, 8.8.15-p2, 8.8.15-p3, 8.8.15-p4, 8.8.15-p5 (+1) — fixed in 8.8.15

How to fix

Upgrade to a fixed version: Zimbra Collaboration 8.8.15. Check the vendor advisory for mitigations.

References

• https://wiki.zimbra.com/wiki/Zimbra_Releases/8.8.15/P7
• https://wiki.zimbra.com/wiki/Zimbra_Releases/8.8.15/P7

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