CVE-2025-40631 HTTP host header injection vulnerability in IceWarp Mail Server

Low 2.0 Published 16 May 2025 Updated 16 May 2025

Attackers can execute arbitrary JavaScript via Host header injection in IceWarp Mail Server, potentially leading to account takeover.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: A user has to click or open something
Fix: None listed

What is CVE-2025-40631?

CVE-2025-40631 is a low-severity cross-site scripting vulnerability in Icewarp Mail Server, published on 16 May 2025. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official description

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.

Weakness: CWE-644

Which versions are affected by CVE-2025-40631?

It affects 1 product.

Products include Icewarp Mail Server.

How do I fix CVE-2025-40631?

No fix has been published for CVE-2025-40631 yet. Limit exposure of the affected software until one is available.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2025-40631 being exploited?

There is no known exploitation of CVE-2025-40631 in the wild and no public exploit code.

Sources

Also known as GHSA-77wj-x762-6p2r.