Auth bypass in Zimbra Collaboration Suite (Zcs)
CVE-2026-93643
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 class: Path Traversal (Directory Traversal)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- wiki.zimbra.com/wiki/Zimbra_Security_Advisories (vendor-advisory)
Frequently asked questions
- What is CVE-2026-93643?
- CVE-2026-93643 is a critical-severity vulnerability in Zimbra Collaboration Suite (Zcs), classified under Path Traversal. CVSS score: 9.8/10. Published 2026-09-25.
- How severe is CVE-2026-93643?
- Critical severity. CVSS v3 base score is 9.8 out of 10.