# CVE-2025-67478: Wrong E-Mail address composition for usernames with a comma and Umlauts in it like "Döe, Jähn"

> Attackers can exploit email composition flaws to potentially expose sensitive user data when usernames contain special characters.

- **Severity:** Not scored
- **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:** Yes
- **Published:** 3 Feb 2026
- **Updated:** 2 Mar 2026
- **Also known as:** DEBIAN-CVE-2025-67478, GHSA-rg4c-x95m-9m4f, UBUNTU-CVE-2025-67478

## What is CVE-2025-67478?

CVE-2025-67478 is a vulnerability in Wikimedia Foundation CheckUser, published on 3 Feb 2026. 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

Vulnerability in Wikimedia Foundation CheckUser. This vulnerability is associated with program files includes/Mail/UserMailer.Php.

This issue affects CheckUser: from * before 1.39.14, 1.43.4, 1.44.1.

## Which versions are affected by CVE-2025-67478?

It affects 1 product.


Products: Mediawiki Checkuser.

## How do I fix CVE-2025-67478?

Upgrade to a fixed version.

## Is CVE-2025-67478 being exploited?

There is no known exploitation of CVE-2025-67478 in the wild and no public exploit code.

## Other vulnerabilities in Wikimedia Foundation CheckUser

- [CVE-2015-2940](https://insights.sbomify.com/CVE-2015-2940/): Cross-site request forgery in n/a (medium 6.8)
- [CVE-2019-18611](https://insights.sbomify.com/CVE-2019-18611/): Information disclosure in n/a (medium 6.5)
- [CVE-2019-16529](https://insights.sbomify.com/CVE-2019-16529/): Information disclosure in n/a (medium 5.3)
- [CVE-2026-34090](https://insights.sbomify.com/CVE-2026-34090/): Suggested investigations: Handle suppressed usernames (medium 4.8)
- [CVE-2025-61658](https://insights.sbomify.com/CVE-2025-61658/): Special:GlobalContributions shows edits on wikis the viewer doesn't have access to (low 1.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-67478 and fix it if it is affected.

What it is: CVE-2025-67478 is a vulnerability in Wikimedia Foundation CheckUser, published on 3 Feb 2026. 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-2025-67478 in the wild and no public exploit code.

Affected product: Wikimedia Foundation CheckUser. 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-2025-67478/ (Markdown: https://insights.sbomify.com/CVE-2025-67478/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-67478
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-67478
- OSV: https://osv.dev/vulnerability/CVE-2025-67478

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-67478/
Summaries are generated and may contain mistakes; the official description above is the record.