# CVE-2021-38321: Custom Menu Plugin <= 1.3.3 Reflected Cross-Site Scripting

> Attackers can inject arbitrary web scripts via the selected_menu parameter in the Custom Menu Plugin, potentially compromising user sessions.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A: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:** 9 Sep 2021
- **Updated:** 5 May 2025
- **Also known as:** GHSA-76xq-mh8g-37w6

## What is CVE-2021-38321?

CVE-2021-38321 is a medium-severity cross-site scripting vulnerability in Custom Menu Plugin, published on 9 Sep 2021. 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

The Custom Menu Plugin WordPress plugin is vulnerable to Reflected Cross-Site Scripting via the selected_menu parameter found in the ~/custom-menus.php file which allows attackers to inject arbitrary web scripts, in versions up to and including 1.3.3.

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

## Which versions are affected by CVE-2021-38321?

It affects 1 product.


Products: Custom-Sub-Menus Project Custom-Sub-Menus.

## How do I fix CVE-2021-38321?

No fix has been published for CVE-2021-38321 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-38321 being exploited?

There is no known exploitation of CVE-2021-38321 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-38321 and fix it if it is affected.

What it is: CVE-2021-38321 is a medium-severity cross-site scripting vulnerability in Custom Menu Plugin, published on 9 Sep 2021. 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-2021-38321 in the wild and no public exploit code.

Affected product: Custom Menu 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-2021-38321/ (Markdown: https://insights.sbomify.com/CVE-2021-38321/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-38321
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-38321
- OSV: https://osv.dev/vulnerability/CVE-2021-38321

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-38321/
Summaries are generated and may contain mistakes; the official description above is the record.