Vulnerability in Zimbra Collaboration Suite

[ Description ]Official description

LDAP filter injection in Zimbra Collaboration Suite 10.1.0 through 10.1.21 allows unauthenticated attackers to alter external LDAP search filters. On domains using search-filter authentication and lazy provisioning, this creates a password oracle for external directory users. Authenticated S/MIME lookups can also return certificates and identity data for unintended directory entries.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• BSI CERT-Bund14 Oct 2026WID-SEC-2026-3977

  Synacor Zimbra: Multiple vulnerabilities Translated from German

  CVE-2026-93635CVE-2026-93637

[ References ]References

• www.rapid7.com/blog/post/ve-breaking-zimbra-identity-boundaries-part-1