Is CVE-2026-93629 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-93629 being exploited in the wild.

How severe is CVE-2026-93629?

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-2026-93629?

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-2026-93629 attacked?

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

Am I affected by CVE-2026-93629?

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-2026-93629: Zimbra Collaboration Suite organizer authentication bypass in calendar invitations

CVE-2026-93629 · Severity: medium · CVSS 5.3 · Published 2026-10-23

Zimbra Collaboration Suite is an email and collaboration platform used by organizations for messaging, calendars, and file sharing. An unauthenticated attacker can forge calendar invitations that appear to come from any user in the system, potentially tricking recipients into accepting meetings with false details and reminders. When automatic invitation insertion is enabled, recipients have no control over whether these fake invitations are accepted.

Technologies: Zimbra Collaboration Suite. Vendors: Zimbra.

Quick answers

Is CVE-2026-93629 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-93629 being exploited in the wild.
How severe is CVE-2026-93629?: 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-2026-93629?: 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-2026-93629 attacked?: It is attacked over the network, in a hosted service.
Am I affected by CVE-2026-93629?: 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 is an authentication bypass in the iCalendar ORGANIZER validation during external email delivery. When a crafted iCalendar REQUEST component arrives via SMTP, the server fails to verify that the sender is authorized to use the specified ORGANIZER identity, allowing an unauthenticated attacker to forge invitations attributed to any user. The attack requires automatic invitation insertion to be enabled; successful exploitation creates an event in the recipient's calendar without sender interaction, but no corresponding entry is created in the impersonated organizer's calendar.

Affected products

Zimbra Collaboration Suite 10.1.16, 10.1.21

Timeline

2026-10-23: disclosed: CVE-2026-93629 published

References

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