Unauth RCE via Path Traversal in OnlyOffice Document Editing on Zimbra
CVE-2026-93643 Published on September 25, 2026
Zimbra Collaboration Suite OnlyOffice Integration Path Traversal Leading to Remote Code Execution via Unauthenticated /downloadas Request
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.
Vulnerability Analysis
CVE-2026-93643 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to be critical as this vulnerability has a high impact to the confidentiality, integrity and availability of this component.
Weakness Types
What is a Directory traversal Vulnerability?
The software uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the software does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
CVE-2026-93643 has been classified to as a Directory traversal vulnerability or weakness.
What is an AuthZ Vulnerability?
The software performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. This allows attackers to bypass intended access restrictions.
CVE-2026-93643 has been classified to as an AuthZ vulnerability or weakness.
Products Associated with CVE-2026-93643
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Affected Versions
Zimbra Collaboration Suite (ZCS):- Before 10.1.21 is affected.