Is CVE-2026-93638 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-93638 being exploited in the wild.

How severe is CVE-2026-93638?

Medium severity, with a CVSS score of 6.1, published 23 October 2026.

Which products and versions are affected?

Zimbra Collaboration Suite 10.1.16, 10.1.17.

Is there a fix for CVE-2026-93638?

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-2026-93638 attacked?

It is attacked over the network.

Am I affected by CVE-2026-93638?

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-2026-93638: Zimbra Collaboration Suite reflected cross-site scripting in login

CVE-2026-93638 · Severity: medium · CVSS 6.1 · Published 2026-10-23

Zimbra Collaboration Suite is an enterprise email and collaboration platform used by organizations for email, calendars, and file sharing. An unauthenticated attacker can exploit a reflected XSS vulnerability in the login page to inject malicious JavaScript that captures user credentials through a fake login form. The vulnerability allows attackers to redirect victims to crafted URLs that execute attacker-controlled code under Zimbra's legitimate domain.

Technologies: Zimbra Collaboration Suite. Vendors: Zimbra.

Quick answers

Is CVE-2026-93638 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-93638 being exploited in the wild.
How severe is CVE-2026-93638?: Medium severity, with a CVSS score of 6.1, published 23 October 2026.
Which products and versions are affected?: Zimbra Collaboration Suite 10.1.16, 10.1.17.
Is there a fix for CVE-2026-93638?: 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-2026-93638 attacked?: It is attacked over the network.
Am I affected by CVE-2026-93638?: 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

A reflected XSS vulnerability exists in the relogin path due to improper HTML encoding of the zrememberme parameter when displaying a two-factor authentication error. The parameter is inserted into a hidden input attribute without sanitization, allowing JavaScript execution in the victim's browser under the Zimbra origin. An attacker crafts a malicious URL that, when clicked by a user, logs out any existing session and renders the injected payload, enabling credential theft via a replacement login form.

Affected products

Zimbra Collaboration Suite 10.1.16, 10.1.17

Timeline

2026-10-23: disclosed

References

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