A reflected cross-site scripting vulnerability in the login page of Zimbra Collaboration Suite (ZCS) allows an unauthenticated attacker to execute JavaScript through the zrememberme parameter. A crafted relogin URL selects a two-factor error display that inserts the parameter into a hidden input attribute without HTML encoding. A victim who opens the URL receives attacker-controlled script and page content under the legitimate Zimbra origin, allowing credential capture through a replacement login form. The relogin path logs out an existing session before rendering the payload, so the demonstrated attack does not inherit that session's mailbox access. ZCS 10.1.16 and 10.1.17 are affected.

Project Subscriptions

No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 23 Oct 2026 13:45:00 +0000

Type Values Removed Values Added
Description A reflected cross-site scripting vulnerability in the login page of Zimbra Collaboration Suite (ZCS) allows an unauthenticated attacker to execute JavaScript through the zrememberme parameter. A crafted relogin URL selects a two-factor error display that inserts the parameter into a hidden input attribute without HTML encoding. A victim who opens the URL receives attacker-controlled script and page content under the legitimate Zimbra origin, allowing credential capture through a replacement login form. The relogin path logs out an existing session before rendering the payload, so the demonstrated attack does not inherit that session's mailbox access. ZCS 10.1.16 and 10.1.17 are affected.
Title Zimbra Collaboration Suite Pre-Authentication Reflected Cross-Site Scripting via Login Page zrememberme Parameter
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'}


Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: rapid7

Published:

Updated: 2026-10-23T13:28:03.891Z

Reserved: 2026-09-18T12:22:38.559Z

Link: CVE-2026-93638

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-23T14:17:57.517

Modified: 2026-10-23T14:17:57.517

Link: CVE-2026-93638

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses