CVE-2026-93629Medium· 5.3▾ SunlitAn 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…
▾ Sunlit zone — Low / medium · no exploitation signal
impact 29.2 · likelihood 0 · exploitation 0
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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.
collaboration_suite <= 10.1.21Refer to the linked advisories for vendor-supplied fixes and affected version ranges.
Connected by shared product, vendor, weakness, or advisory.
CVE-2026-93627Medium· 5.3Zimbra Collaboration Suite Calendar Processing Authentication Bypass via Forged iCalendar CANCEL/REQUEST Organizer
CVE-2026-93628Medium· 5.3Zimbra Collaboration Suite Calendar Processing Authentication Bypass via Forged iCalendar REPLY Attendee Response
CVE-2026-93631High· 7.1Zimbra Collaboration Suite OAuth Extension Cross-Site Request Forgery Enables Account Linking
CVE-2026-93630Medium· 4.3Zimbra Collaboration Suite Email HTML Sanitizer Bypass via Hostname Canonicalization
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