# CVE-2025-59839: Star Citizen EmbedVideo Extension Stored XSS through wikitext caused by usage of non-reserved data attributes

> Stored XSS in MediaWiki EmbedVideo extension allows attackers to inject scripts via wikitext, potentially compromising user sessions.

- **Severity:** High 8.6 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 25 Sep 2025
- **Updated:** 25 Sep 2025
- **Also known as:** GHSA-4j5h-mvj3-m48v

## What is CVE-2025-59839?

CVE-2025-59839 is a high-severity cross-site scripting vulnerability in StarCitizenWiki mediawiki-extensions-EmbedVideo, published on 25 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The EmbedVideo Extension is a MediaWiki extension which adds a parser function called #ev and various parser tags for embedding video clips from various video sharing services. In versions 4.0.0 and prior, the EmbedVideo extension allows adding arbitrary attributes to an HTML element, allowing for stored XSS through wikitext. This issue has been patched via commit 4e075d3.

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

## Which versions are affected by CVE-2025-59839?

2 open source packages ship an affected version, including starcitizenwiki/embedvideo. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `starcitizenwiki/embedvideo` | Packagist | All versions to 4.0.0 | None |
| `starcitizenwiki/embedvideo` | Packagist | All versions to 4.0.0 | None |

Products: Star-Citizen Embedvideo.

## How do I fix CVE-2025-59839?

No fix has been published for CVE-2025-59839 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-59839 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-59839 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-59839 and fix it if it is affected.

What it is: CVE-2025-59839 is a high-severity cross-site scripting vulnerability in StarCitizenWiki mediawiki-extensions-EmbedVideo, published on 25 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-59839 exists.

Affected packages and fixed versions:
- starcitizenwiki/embedvideo (Packagist): affected all versions up to 4.0.0; no fix listed
- starcitizenwiki/embedvideo (Packagist): affected all versions up to 4.0.0; no fix listed

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-2025-59839/ (Markdown: https://insights.sbomify.com/CVE-2025-59839/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-59839
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-59839
- OSV: https://osv.dev/vulnerability/CVE-2025-59839

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-59839/
Summaries are generated and may contain mistakes; the official description above is the record.