CVE-2026-93643

CRITICAL 9.8

Zimbra Collaboration Suite OnlyOffice Integration Path Traversal Leading to Remote Code Execution via Unauthenticated /downloadas Request

CVSS Score

9.8

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-22 CWE-863
Vendor	zimbra
Product	zimbra collaboration suite (zcs)
Published	Sep 25, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Affected Versions

Zimbra / Zimbra Collaboration Suite (ZCS)

0 < 10.1.21

References

NVD ↗ CVE.org ↗ EPSS Data ↗

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

Credits

Jonah Burgess (CryptoCat), Senior Security Researcher, Rapid7