# CVE-2025-3929: Stored XSS vulnerability in MDaemon Email Server

> Remote attackers can execute arbitrary JavaScript in webmail users' browsers via crafted HTML emails, potentially accessing user data.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 29 Apr 2025
- **Updated:** 29 Apr 2025
- **Also known as:** GHSA-jgvv-fw39-8435

## What is CVE-2025-3929?

CVE-2025-3929 is a medium-severity cross-site scripting vulnerability in MDaemon Email Server, published on 29 Apr 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

An XSS issue was discovered in MDaemon Email Server version 25.0.1 and below. An attacker can send a specially crafted HTML e-mail message with JavaScript in an img tag. This could allow a remote attacker to load arbitrary JavaScript code in the context of a webmail user's browser window, and access user data.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2025-3929?

It affects 1 product.


Products: Mdaemon Email Server.

## How do I fix CVE-2025-3929?

No fix has been published for CVE-2025-3929 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-3929 being exploited?

There is no known exploitation of CVE-2025-3929 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-3929 and fix it if it is affected.

What it is: CVE-2025-3929 is a medium-severity cross-site scripting vulnerability in MDaemon Email Server, published on 29 Apr 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2025-3929 in the wild and no public exploit code.

Affected product: MDaemon Email 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-2025-3929/ (Markdown: https://insights.sbomify.com/CVE-2025-3929/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-3929
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-3929
- OSV: https://osv.dev/vulnerability/CVE-2025-3929

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-3929/
Summaries are generated and may contain mistakes; the official description above is the record.