Is CVE-2026-93639 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-93639 being exploited in the wild.

How severe is CVE-2026-93639?

High severity, with a CVSS score of 8.7, published 23 October 2026.

Which products and versions are affected?

Zimbra Collaboration Suite 10.1.16, 10.1.20.

Is there a fix for CVE-2026-93639?

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-2026-93639 attacked?

It is attacked over the network, in a web application.

Am I affected by CVE-2026-93639?

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-2026-93639: Zimbra Collaboration Suite authorization bypass in Zimlet configuration

CVE-2026-93639 · Severity: high · CVSS 8.7 · Published 2026-10-23

Zimbra Collaboration Suite is a self-hosted email and collaboration platform used by enterprises for email, calendars, and file sharing. A missing authorization check allows a delegated administrator with limited privileges to modify global Zimlet configuration and inject attacker-controlled domains into the service proxy allowlist. When a legitimate user visits a crafted URL, the browser loads attacker-controlled HTML under Zimbra's trusted domain, enabling JavaScript to read emails, contacts, and perform authenticated actions as the victim.

Technologies: Zimbra Collaboration Suite. Vendors: Zimbra.

Quick answers

Is CVE-2026-93639 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-93639 being exploited in the wild.
How severe is CVE-2026-93639?: High severity, with a CVSS score of 8.7, published 23 October 2026.
Which products and versions are affected?: Zimbra Collaboration Suite 10.1.16, 10.1.20.
Is there a fix for CVE-2026-93639?: 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-2026-93639 attacked?: It is attacked over the network, in a web application.
Am I affected by CVE-2026-93639?: 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 a missing authorization check in the ConfigureZimletRequest SOAP handler that fails to validate whether a delegated administrator has permission to modify global Zimlet settings. An attacker with a delegated-administrator account can upload malicious Zimlet configuration and add an arbitrary domain to the proxy allowlist of the default class of service. When a signed-in user visits a crafted /service/proxy URL pointing to the attacker's domain, Zimbra serves the attacker's HTML under its own origin, allowing the injected JavaScript to access session cookies and perform authenticated mailbox operations.

Affected products

Zimbra Collaboration Suite 10.1.16, 10.1.20

Timeline

2026-10-23: disclosed

References

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