# CVE-2020-4038: Reflected XSS in GraphQL Playground

> Reflected XSS in GraphQL Playground allows attackers to execute arbitrary scripts via unsanitized input in the renderPlaygroundPage method.

- **Severity:** High 7.4 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:H/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:** Yes
- **Published:** 8 Jun 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-4852-vrh7-28rf

## What is CVE-2020-4038?

CVE-2020-4038 is a high-severity cross-site scripting vulnerability in prisma-labs graphql-playground, published on 8 Jun 2020. 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

GraphQL Playground (graphql-playground-html NPM package) before version 1.6.22 have a severe XSS Reflection attack vulnerability. All unsanitized user input passed into renderPlaygroundPage() method could trigger this vulnerability. This has been patched in graphql-playground-html version 1.6.22. Note that some of the associated dependent middleware packages are also affected including but not limited to graphql-playground-middleware-express before version 1.7.16, graphql-playground-middleware-koa before version 1.6.15, graphql-playground-middleware-lambda before version 1.7.17, and graphql-playground-middleware-hapi before 1.6.13.

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

## Which versions are affected by CVE-2020-4038?

2 open source packages ship an affected version, including graphql-playground-html. It affects 5 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `graphql-playground-html` | npm | All versions | 1.6.22 |
| `graphql-playground-html` | npm | All versions | 1.6.22 |

Products: Prisma Graphql-Playground-Html, Prisma Graphql-Playground-Middleware-Express, Prisma Graphql-Playground-Middleware-Hapi, Prisma Graphql-Playground-Middleware-Koa, Prisma Graphql-Playground-Middleware-Lambda.

## How do I fix CVE-2020-4038?

Upgrade graphql-playground-html to 1.6.22 or later.

## Is CVE-2020-4038 being exploited?

There is no known exploitation of CVE-2020-4038 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-4038 and fix it if it is affected.

What it is: CVE-2020-4038 is a high-severity cross-site scripting vulnerability in prisma-labs graphql-playground, published on 8 Jun 2020. 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-2020-4038 in the wild and no public exploit code.

Affected packages and fixed versions:
- graphql-playground-html (npm): affected all versions; fixed in 1.6.22
- graphql-playground-html (npm): affected all versions; fixed in 1.6.22

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-2020-4038/ (Markdown: https://insights.sbomify.com/CVE-2020-4038/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-4038
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-4038
- OSV: https://osv.dev/vulnerability/CVE-2020-4038

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-4038/
Summaries are generated and may contain mistakes; the official description above is the record.