CVE-2026-93627

An organizer authentication vulnerability in the email calendar processing of Zimbra Collaboration Suite (ZCS) allows an unauthenticated sender to cancel or modify an existing meeting in a recipient's calendar. Zimbra accepts iCalendar CANCEL and REQUEST components without verifying that the email sender is authorized to act as the supplied organizer. An attacker who knows the meeting UID and organizer address can supply a non-outdated sequence number to move the recipient's meeting to Trash or replace its details. Processing occurs automatically during email delivery without recipient interaction. ZCS 10.1.16 and 10.1.21 are affected.
Configurations

No configuration.

History

23 Oct 2026, 14:17

Type Values Removed Values Added
New CVE

Information

Published : 2026-10-23 14:17

Updated : 2026-10-28 20:18


NVD link : CVE-2026-93627

Mitre link : CVE-2026-93627

CVE.ORG link : CVE-2026-93627


JSON object : View

Products Affected

No product.

CWE
CWE-290

Authentication Bypass by Spoofing