# CVE-2019-18611: Information disclosure in n/a

> Users with CheckUser access could view sensitive oversighted edit summaries via the API, exposing hidden data.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 29 Oct 2019
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-w3xh-g4rp-pcfc

## What is CVE-2019-18611?

CVE-2019-18611 is a medium-severity vulnerability in n/a, published on 29 Oct 2019. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

An issue was discovered in the CheckUser extension through 1.34 for MediaWiki. Certain sensitive information within oversighted edit summaries made available via the MediaWiki API was potentially visible to users with various levels of access to this extension. Said users should not have been able to view these oversighted edit summaries via the MediaWiki API.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2019-18611?

It affects 1 product.


Products: Mediawiki Checkuser.

## How do I fix CVE-2019-18611?

No fix has been published for CVE-2019-18611 yet. Limit exposure of the affected software until one is available.

## Is CVE-2019-18611 being exploited?

There is no known exploitation of CVE-2019-18611 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2015-2940](https://insights.sbomify.com/CVE-2015-2940/): Cross-site request forgery in n/a (medium 6.8)
- [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)
- [CVE-2025-61648](https://insights.sbomify.com/CVE-2025-61648/): Stored XSS through system messages in CheckUser (not scored)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2019-18611 and fix it if it is affected.

What it is: CVE-2019-18611 is a medium-severity vulnerability in n/a, published on 29 Oct 2019. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2019-18611 in the wild and no public exploit code.

Affected product: n/a. 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-2019-18611/ (Markdown: https://insights.sbomify.com/CVE-2019-18611/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2019-18611
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-18611
- OSV: https://osv.dev/vulnerability/CVE-2019-18611

---
From sbomify Insights: https://insights.sbomify.com/CVE-2019-18611/
Summaries are generated and may contain mistakes; the official description above is the record.