Zimbra 10.1 Reflected XSS in login via zrememberme param
CVE-2026-93638 Published on October 23, 2026
Zimbra Collaboration Suite Pre-Authentication Reflected Cross-Site Scripting via Login Page zrememberme Parameter
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.
Vulnerability Analysis
CVE-2026-93638 is exploitable with network access, requires user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality and integrity, and no impact on availability.
Weakness Type
What is a XSS Vulnerability?
The software does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
CVE-2026-93638 has been classified to as a XSS vulnerability or weakness.
Products Associated with CVE-2026-93638
Want to know whenever a new CVE is published for Zimbra Collaboration Suite? stack.watch will email you.
Affected Versions
Zimbra Collaboration Suite:- Before and including 10.1.17 is affected.