CVE-2025-34404

Severity CVSS v4.0:
MEDIUM
Type:
CWE-79 Cross-Site Scripting (XSS)
Publication date:
09/12/2025
Last modified:
09/12/2025

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 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.

Vulnerable products and versions

CPE From Up to
cpe:2.3:a:mailenable:mailenable:*:*:*:*:standard:*:*:* 10.54 (excluding)