All vulnerabilities
CVE-2026-10631

Zimbra Collaboration Suite EWS Extension Authorization Bypass via Crafted Composite Folder/Item Identifier

Zimbra Zimbra Collaboration SuiteApplications & CMS
Open in ThreatlineRecord JSON
CVSS
6.5Medium
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.21%Chance of exploitation activity in the next 30 days, higher than 11% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in10.1.20Fixed versionCVE List
Published8 Oct 2026Updated 8 Oct 2026CVE List

What fixes it

  • 10.1.20Zimbra Collaboration SuiteCVE List

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Timeline

  1. 8 Oct 2026, 16:25 UTCPublishedCVE List
  2. 14 Oct 2026, 13:00 UTCExploit code publicRapid7

Reports 1

1 outlet mention it. Reports are not confirmation; each links to its source.

Description

An authorization bypass in the EWS FindItem handler of Zimbra Collaboration Suite 10.1.0 through 10.1.19 allows an authenticated user with EWS enabled to read complete mailbox items, including raw MIME and attachments, from arbitrary local accounts without a share or delegation grant.

Text from CVE List

Affected versions 1

  • Zimbra Collaboration Suiteaffected: all versions before 10.1.20CVE List

References 1