Security Advisory

CVE-2025-34404

CVE vulnerability detail — eXtreme Datacenter Security Operations

Published 2025-12-09 18:07:47
Last updated 2026-05-14 02:08:25
Assigner VulnCheck
State PUBLISHED

Description

MailEnable versions prior to 10.54 contain a reflected cross-site scripting (XSS) vulnerability in the InstanceScope parameter of /Mondo/lang/sys/Forms/CAL/compose.aspx. The InstanceScope value is not properly sanitized when processed via a GET request and is reflected inside a <script> block in the JavaScript variable var gInstanceScope. By supplying a crafted payload that terminates the existing PageLoad() function, inserts attacker-controlled script, and comments out remaining code, a remote attacker can execute arbitrary JavaScript in a victim’s browser. Successful exploitation can redirect victims to malicious sites, steal non-HttpOnly cookies, inject arbitrary HTML or CSS, and perform actions as the authenticated user.