CVE-2025-40631: Icewarp Mail Server

Medium severity, CVSS 6.1. EPSS: 0.2% chance of exploitation in the next 30 days.

HTTP host header injection vulnerability in Icewarp Mail Server affecting version 11.4.0. By modifying the Host header and adding a payload, arbitrary JavaScript code can be executed on page load. The user must interact with a malicious link to be redirected.

Affected products

• Icewarp Mail Server: version 11.4.0 only

Published 2025-05-16. Last modified 2026-06-17.