# CVE-2021-36899: Cross-site scripting in Asset CleanUp: Page Speed Booster (WordPress plugin)

> Authenticated administrators can inject malicious scripts via reflected XSS in the Asset CleanUp plugin, potentially compromising user sessions.

- **Severity:** Medium 4.8 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 11 Oct 2022
- **Updated:** 28 Apr 2026
- **Also known as:** GHSA-q34g-xwpj-xqx4

## What is CVE-2021-36899?

CVE-2021-36899 is a medium-severity cross-site scripting vulnerability in Gabe Livan Asset CleanUp: Page Speed Booster (WordPress plugin), published on 11 Oct 2022. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

Authenticated (admin+) Reflected Cross-Site Scripting (XSS) vulnerability in Gabe Livan's Asset CleanUp: Page Speed Booster plugin <= 1.3.8.4 at WordPress.

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

## Which versions are affected by CVE-2021-36899?

It affects 1 product.


Products: Asset Cleanup\  Page Speed Booster Project.

## How do I fix CVE-2021-36899?

No fix has been published for CVE-2021-36899 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-36899 being exploited?

There is no known exploitation of CVE-2021-36899 in the wild and no public exploit code.

## Other vulnerabilities in Gabe Livan Asset CleanUp: Page Speed Booster (WordPress plugin)

- [CVE-2021-24937](https://insights.sbomify.com/CVE-2021-24937/): Asset CleanUp < 1.3.8.5 - Reflected Cross-Site Scripting (medium 6.1)
- [CVE-2021-24983](https://insights.sbomify.com/CVE-2021-24983/): Asset CleanUp < 1.3.8.5 - Reflected Cross-Site Scripting via AJAX Action (medium 6.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-36899 and fix it if it is affected.

What it is: CVE-2021-36899 is a medium-severity cross-site scripting vulnerability in Gabe Livan Asset CleanUp: Page Speed Booster (WordPress plugin), published on 11 Oct 2022. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2021-36899 in the wild and no public exploit code.

Affected product: Gabe Livan Asset CleanUp: Page Speed Booster (WordPress 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-2021-36899/ (Markdown: https://insights.sbomify.com/CVE-2021-36899/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-36899
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-36899
- OSV: https://osv.dev/vulnerability/CVE-2021-36899

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From sbomify Insights: https://insights.sbomify.com/CVE-2021-36899/
Summaries are generated and may contain mistakes; the official description above is the record.