CVE-2026-10631: CWE-639 Authorization bypass through User-Controlled key in Zimbra Zimbra Collaboration Suite
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.
CVSS v3.1
Score 6.5medium
Affected software
Zimbra
Zimbra Collaboration Suite
pkg:github/zimbra/zimbra-collaboration-suiteRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-10631) affects Zimbra Collaboration Suite versions 10.1.0 up to but not including 10.1.20. It is caused by an authorization bypass in the Exchange Web Services (EWS) FindItem handler, classified as CWE-639 (Authorization Bypass Through User-Controlled Key). An authenticated user with EWS enabled can exploit this flaw to access full mailbox contents of other local accounts without proper authorization, including raw MIME data and attachments.
Potential Impact
The impact is a confidentiality breach where an authenticated user can read sensitive mailbox data from other users without permission. The vulnerability does not affect integrity or availability. The CVSS 3.1 base score is 6.5 (medium severity), reflecting network attack vector, low attack complexity, required privileges, no user interaction, and high confidentiality impact.
Mitigation Recommendations
No official patch or vendor advisory is provided in the input data. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict EWS access to trusted users only and monitor for unusual mailbox access patterns.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- rapid7
- Date Reserved
- 2026-06-02T14:57:14.369Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ac7c7552cdf04f6562a0002
Added to database: 10/08/2026, 16:39:49 UTC
Last enriched: 10/08/2026, 16:48:31 UTC
Last updated: 10/09/2026, 05:48:07 UTC
Views: 8
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