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CVE-2026-93629EUVD-2026-108965GHSA-X4QW-FPGG-G7X4

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

Published
Last modified
published
Not listed in CISA KEV
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: yes
  • Technical impact: partial

Summary

Zimbra Collaboration Suite (ZCS), an email and calendar platform, is affected by this vulnerability. An unauthenticated attacker can send an email with a forged calendar invitation that appears to come from another user, creating an event with attacker-chosen details and reminders in the recipient's calendar without any action by the recipient.

Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.

Read the original 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.

Timeline

  1. CVE published
  2. First seen by cve.now
  3. CISA SSVC assessment

    Exploitation: none · Automatable: yes · Technical impact: partial

  4. Record last updated

Affected versions

  • Zimbra Zimbra Collaboration Suite

    through 10.1.21

References 2

wiki.zimbra.com

rapid7.com