Unauthenticated remote RCE in widely used Zimbra collaboration servers (OnlyOffice integration) enabling system-level compromise across enterprises.
CVE-2026-93643
Unauthenticated RCE in Zimbra OnlyOffice via path-traversal in public Briefcase.
Is CVE-2026-93643 being exploited?
Not confirmed. CVE-2026-93643 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked.
How severe is CVE-2026-93643?
CVE-2026-93643 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-93643?
Not known from our data. No patch reference has been recorded for CVE-2026-93643, which is not the same as no patch existing — a fix may have shipped without a tagged reference, or after this record was written. The vendor advisory is the only authority on whether a fix exists, and mitigations may be available regardless.
What does CVE-2026-93643 affect?
CVE-2026-93643 affects Zimbra Collaboration Suite, OnlyOffice/Document Editing integration, Zimbra Briefcase (public documents). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-93643?
Apply vendor patch ASAP; if unavailable, disable OnlyOffice or public Briefcase access.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated path-traversal write enabling command execution as 'zimbra' user, allowing full system compromise.
Immediate action required
- affected< 10.1.21
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.