# CVE-2018-25249: MyBB My Arcade Plugin 1.3 Persistent XSS via Comment

> Authenticated users can inject malicious scripts via arcade game score comments, leading to persistent XSS attacks against other users.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 4 Apr 2026
- **Updated:** 24 May 2026
- **Also known as:** GHSA-4mc8-7jpg-4r7r

## What is CVE-2018-25249?

CVE-2018-25249 is a medium-severity cross-site scripting vulnerability in MyBB My Arcade Plugin, published on 4 Apr 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

MyBB My Arcade Plugin 1.3 contains a persistent cross-site scripting vulnerability that allows authenticated users to inject malicious scripts through arcade game score comments. Attackers can add crafted HTML and JavaScript payloads in the comment field that execute when other users view or edit the comment.

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

## Which versions are affected by CVE-2018-25249?

It affects 1 product.


Products: Mybb My Arcade.

## How do I fix CVE-2018-25249?

No fix has been published for CVE-2018-25249 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-25249 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2018-25249 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-25249 and fix it if it is affected.

What it is: CVE-2018-25249 is a medium-severity cross-site scripting vulnerability in MyBB My Arcade Plugin, published on 4 Apr 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2018-25249 exists.

Affected product: MyBB My Arcade Plugin. 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-2018-25249/ (Markdown: https://insights.sbomify.com/CVE-2018-25249/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-25249
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-25249
- OSV: https://osv.dev/vulnerability/CVE-2018-25249

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-25249/
Summaries are generated and may contain mistakes; the official description above is the record.