# CVE-2021-39202: WordPress 5.8 beta: Stored Cross-Site Scripting (XSS) vulnerability in widget


- **Severity:** High 7.6 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 9 Sep 2021
- **Updated:** 4 Aug 2024
- **Also known as:** UBUNTU-CVE-2021-39202

## What is CVE-2021-39202?

CVE-2021-39202 is a high-severity vulnerability in Wordpress Wordpress, published on 9 Sep 2021. 

### Official description

WordPress is a free and open-source content management system written in PHP and paired with a MySQL or MariaDB database. In affected versions the widgets editor introduced in WordPress 5.8 beta 1 has improper handling of HTML input in the Custom HTML feature. This leads to stored XSS in the custom HTML widget. This has been patched in WordPress 5.8. It was only present during the testing/beta phase of WordPress 5.8.

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

## Which versions are affected by CVE-2021-39202?

It affects 1 product.


Products: Wordpress Wordpress.

## How do I fix CVE-2021-39202?

No fix has been published for CVE-2021-39202 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-39202 being exploited?

There is no known exploitation of CVE-2021-39202 in the wild and no public exploit code.

## Other vulnerabilities in Wordpress Wordpress

- [CVE-2026-63030](https://insights.sbomify.com/CVE-2026-63030/): WordPress Core Interpretation Conflict (critical 9.8, exploited in the wild)
- [CVE-2026-87902](https://insights.sbomify.com/CVE-2026-87902/): WordPress Core Remote File Inclusion (high 8.1, exploited in the wild)
- [CVE-2026-60137](https://insights.sbomify.com/CVE-2026-60137/): WordPress Core SQL Injection (medium 5.9, exploited in the wild)
- [CVE-2012-2399](https://insights.sbomify.com/CVE-2012-2399/): Cross-site scripting in n/a (critical 10.0)
- [CVE-2012-2400](https://insights.sbomify.com/CVE-2012-2400/): Other in n/a (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-39202 and fix it if it is affected.

What it is: CVE-2021-39202 is a high-severity vulnerability in Wordpress Wordpress, published on 9 Sep 2021. 
Exploitation: There is no known exploitation of CVE-2021-39202 in the wild and no public exploit code.

Affected product: Wordpress Wordpress. 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-2021-39202/ (Markdown: https://insights.sbomify.com/CVE-2021-39202/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-39202
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-39202
- OSV: https://osv.dev/vulnerability/CVE-2021-39202

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-39202/
Summaries are generated and may contain mistakes; the official description above is the record.