Is CVE-2026-93627 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-93627 being exploited in the wild.

How severe is CVE-2026-93627?

Medium severity, with a CVSS score of 5.3, published 23 October 2026.

Which products and versions are affected?

Zimbra Collaboration Suite 10.1.16, 10.1.21.

Is there a fix for CVE-2026-93627?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-93627 attacked?

It is attacked over the network, in a hosted service.

Am I affected by CVE-2026-93627?

Check whether you run Zimbra Collaboration Suite at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-93627: Zimbra Collaboration Suite organizer authentication bypass in calendar processing

CVE-2026-93627 · Severity: medium · CVSS 5.3 · Published 2026-10-23

Zimbra Collaboration Suite is an email and calendar platform used by organizations to manage communications and schedules. An unauthenticated attacker can delete or modify meetings in recipients' calendars by sending forged email messages, since Zimbra does not verify that the sender is authorized to act as the meeting organizer. This can lead to schedule disruption, missed appointments, and social engineering opportunities.

Technologies: Zimbra Collaboration Suite. Vendors: Zimbra.

Quick answers

Is CVE-2026-93627 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-93627 being exploited in the wild.
How severe is CVE-2026-93627?: Medium severity, with a CVSS score of 5.3, published 23 October 2026.
Which products and versions are affected?: Zimbra Collaboration Suite 10.1.16, 10.1.21.
Is there a fix for CVE-2026-93627?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-93627 attacked?: It is attacked over the network, in a hosted service.
Am I affected by CVE-2026-93627?: Check whether you run Zimbra Collaboration Suite at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability exists in ZCS's iCalendar processing during email delivery, where CANCEL and REQUEST components are processed without verifying sender authorization against the organizer address. An attacker who knows the meeting UID and organizer email can craft malicious iCalendar messages with non-outdated sequence numbers to move meetings to Trash or replace meeting details; processing occurs automatically without recipient interaction. The flaw affects ZCS 10.1.16 and 10.1.21.

Affected products

Zimbra Collaboration Suite 10.1.16, 10.1.21

Timeline

2026-10-23: disclosed

References

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