# CVE-2025-61927: Happy-DOM has VM Context Escape

> Happy-DOM allows VM context escape via JavaScript evaluation, enabling remote code execution on the host system.

- **Severity:** High 7.2 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:A/VC:L/VI:H/VA:H/SC:H/SI:H/SA:H`)
- **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:** Yes
- **Published:** 10 Oct 2025
- **Updated:** 10 Oct 2025
- **Also known as:** CLSA-2026-1789467187, CLSA-2026-1792254627, CLSA-2026-1792866960, GHSA-37j7-fg3j-429f

## What is CVE-2025-61927?

CVE-2025-61927 is a high-severity code injection vulnerability in capricorn86 happy-dom, published on 10 Oct 2025. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.

### Official description

Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. Happy DOM v19 and lower contains a security vulnerability that puts the owner system at the risk of RCE (Remote Code Execution) attacks. A Node.js VM Context is not an isolated environment, and if the user runs untrusted JavaScript code within the Happy DOM VM Context, it may escape the VM and get access to process level functionality. It seems like what the attacker can get control over depends on if the process is using ESM or CommonJS. With CommonJS the attacker can get hold of the `require()` function to import modules. Happy DOM has JavaScript evaluation enabled by default. This may not be obvious to the consumer of Happy DOM and can potentially put the user at risk if untrusted code is executed within the environment. Version 20.0.0 patches the issue by changing JavaScript evaluation to be disabled by default.

Weakness: CWE-94 (Improper Control of Generation of Code)

## Which versions are affected by CVE-2025-61927?

2 open source packages ship an affected version, including happy-dom.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `happy-dom` | npm | All versions | 20.0.0 |
| `happy-dom` | npm | All versions | 20.0.0 |

## How do I fix CVE-2025-61927?

Upgrade happy-dom to 20.0.0 or later.

## Is CVE-2025-61927 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-61927 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-61927 and fix it if it is affected.

What it is: CVE-2025-61927 is a high-severity code injection vulnerability in capricorn86 happy-dom, published on 10 Oct 2025. An attacker needs administrator access to exploit it, 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-2025-61927 exists.

Affected packages and fixed versions:
- happy-dom (npm): affected all versions; fixed in 20.0.0
- happy-dom (npm): affected all versions; fixed in 20.0.0

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-2025-61927/ (Markdown: https://insights.sbomify.com/CVE-2025-61927/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-61927
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-61927
- OSV: https://osv.dev/vulnerability/CVE-2025-61927

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-61927/
Summaries are generated and may contain mistakes; the official description above is the record.