What’s Vulnerable › Vulnerabilities

CVE-2026-93643: Zimbra Collaboration Suite OnlyOffice Integration Path Traversal Leading to Remote Code Execution via Unauthenticated /downloadas Request

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.0% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-25 · updated 2026-09-29
• Weakness: CWE-22

Description

When OnlyOffice/Document Editing is available, an unauthenticated remote attacker with access to an existing supported public Briefcase document can abuse unsigned save fields to perform path-traversal writes and execute commands as zimbra.

Affected products

• Zimbra Collaboration Suite (ZCS): before 10.1.21 — fixed in 10.1.21

How to fix

Upgrade to a fixed version: Zimbra Collaboration Suite (ZCS) 10.1.21. Check the vendor advisory for mitigations.

References

• https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories

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