VULNERABILITY INTELLIGENCE

CVE-2025-34404

CVSS score5.3 MEDIUM
EPSS probability0.40%
CISA KEVNot currently listed
Published2025-12-09
Last modified2026-10-14
CVSS vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N

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.

Weakness classification

  • CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Primary references