CVE-2026-10631

MEDIUM 6.5

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

CVSS Score

6.5

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-639
Vendor	zimbra
Product	zimbra collaboration suite
Published	Oct 8, 2026

Stay Ahead of the Next One

Get instant alerts for zimbra zimbra collaboration suite

Be the first to know when new medium vulnerabilities affecting zimbra zimbra collaboration suite are published — delivered to Slack, Telegram or Discord.

Get Free Alerts → Free · No credit card · 60 sec setup

CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None

Affected Versions

Zimbra / Zimbra Collaboration Suite

0 < 10.1.20

References

NVD ↗ CVE.org ↗ EPSS Data ↗

wiki.zimbra.com: https://wiki.zimbra.com/wiki/Zimbra_Security_Advisories

Credits

Jonah Burgess (CryptoCat), Senior Security Researcher, Rapid7