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CVE PROGRAM SOURCE RECORD5.3 Medium

CVE-2026-93629

Zimbra Collaboration Suite Calendar Processing Authentication Bypass via Forged iCalendar REQUEST Organizer Identity

Description

An organizer authentication vulnerability in Zimbra Collaboration Suite (ZCS) allows an unauthenticated email sender to insert calendar invitations attributed to another user. The email delivery path permits external invitations but does not verify that the message sender is authorized to use the iCalendar ORGANIZER identity. When automatic invitation insertion is enabled, a crafted REQUEST component creates an event containing attacker-selected meeting details and reminders under a forged organizer without recipient interaction. No corresponding event is created in the claimed organizer's calendar. ZCS 10.1.16 and 10.1.21 are affected.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Zimbra Zimbra Collaboration Suite

Default version status: unaffected

  • 0 to ≤ 10.1.21affected

References