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

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

- **Severity:** Low 2.0 (`CVSS:4.0/AV:A/AC:H/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N`)
- **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 available:** No
- **Published:** 16 May 2025
- **Updated:** 16 May 2025
- **Also known as:** GHSA-77wj-x762-6p2r

## 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 (Improper Neutralization of HTTP Headers for Scripting Syntax)

## Which versions are affected by CVE-2025-40631?

It affects 1 product.


Products: 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.

## Is CVE-2025-40631 being exploited?

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

## Other vulnerabilities in Icewarp Mail Server

- [CVE-2023-39699](https://insights.sbomify.com/CVE-2023-39699/): Path traversal in n/a (critical 9.8)
- [CVE-2020-14066](https://insights.sbomify.com/CVE-2020-14066/): File upload in n/a (high 8.8)
- [CVE-2019-12593](https://insights.sbomify.com/CVE-2019-12593/): Path traversal in n/a (high 7.5)
- [CVE-2015-1503](https://insights.sbomify.com/CVE-2015-1503/): Path traversal in n/a (high 7.5)
- [CVE-2020-14064](https://insights.sbomify.com/CVE-2020-14064/): Missing authorization in n/a (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-40631 and fix it if it is affected.

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

Affected product: Icewarp Mail Server. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-40631/ (Markdown: https://insights.sbomify.com/CVE-2025-40631/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-40631
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-40631
- OSV: https://osv.dev/vulnerability/CVE-2025-40631

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-40631/
Summaries are generated and may contain mistakes; the official description above is the record.