Zimbra Collaboration Suite EWS Extension Authorization Bypass via Crafted Composite Folder/Item Identifier
Published Oct 8, 2026 · Updated Nov 3, 2026
Original summary
Normalized public record · Updated Nov 3, 2026
Zimbra Collaboration Suite EWS Extension Authorization Bypass via Crafted Composite Folder/Item Identifier
Publisher and source text is retained separately from QFinch interpretation.
QFinch assessment
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.
Evidence: public source recordsAffected products
| Affected package, product or range | Fix status |
|---|---|
| Consult the referenced vendor advisory for affected versions. | Consult source advisory |
Matching a version is only one part of assessing exposure. QFinch has not assessed your environment on this public page.
Remediation
Apply the vendor-supported fixed release or mitigation, then verify the affected component is no longer reachable.
- Confirm the affected product and reachable code path exist in your environment.
- Apply the vendor-supported patch or mitigation from the primary advisory.
- Rescan the exact deployed revision and retain verification evidence.
Evidence coverage
- SSVC priority
- LOW
- Confidence
- Not available
- Aliases
- None reported
Scores appear only when corresponding evidence exists. Missing data is never interpreted as zero risk.
Sources and record history
Record history
Published Oct 8, 2026 · Last refreshed Nov 3, 2026