CVE-2026-93627

The record

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 An attacker who knows the meeting UID and organizer address can supply a non-outdated sequence number to move the recipient's meeting to Trash or replace its details.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.

Affected packages

Related vulnerabilities

• CVE-2026-63115 ActivityPub is a multi-tenant ActivityPub server for Ghost, built with Fedify. CWE-290
• CVE-2026-104623 A security vulnerability exists in the authorization handling for the local (management)… CWE-290
• CVE-2026-119703 xiaozhi-esp32-server through 0.9.8 contains an authentication bypass vulnerability in… CWE-290
• CVE-2026-104615 A security vulnerability was discovered in SUSE Rancher Fleet's cluster registration… CWE-290
• CVE-2026-91914 Dell OpenManage Enterprise, versions prior to 4.8.0, contains an Authentication Bypass by… CWE-290
• CVE-2026-119425 OPNsense core 26.1.6 through 26.7.7 contains an authentication bypass vulnerability in… CWE-290
• CVE-2026-115962 Authentication Bypass by Spoofing vulnerability in myCred myCred mycred allows Identity… CWE-290
• CVE-2026-118653 Echo is a Go web framework. CWE-290