CVE-2026-93643
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
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.
- Record
CVE-2026-93643- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-22, CWE-863
- Updated
- 2026-11-02
EUVDEUVD-2026-87101
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.
- Record
EUVD-2026-87101- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-4g2j-34p9-p684
When OnlyOffice/Document Editing is available, an unauthenticated remote attacker with access to...
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.
- Record
GHSA-4g2j-34p9-p684- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-22
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-93643- CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-22, CWE-863
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-93643 is a critical vulnerability (CVSS 9.8) in Synacor Zimbra Collaboration Suite (zcs), published September 25, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.96%, the 61st percentile. No source names a fixed version.