Happy Dom

Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. Versions prior to 20.8.9 may attach cookies from the current page origin (`window.location`) instead of the request target URL when `fetch(..., { credentials: "include" })` is used. This can leak cookies from origin A to destination B. Version 20.8.9 fixes the issue.

Published: 2026-03-27T21:17:24.777Z
Updated: 2026-07-15T01:04:37.919Z

Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. In versions 15.10.0 through 20.8.7, a code injection vulnerability in `ECMAScriptModuleCompiler` allows an attacker to achieve Remote Code Execution (RCE) by injecting arbitrary JavaScript expressions inside `export { }` declarations in ES module scripts processed by happy-dom. The compiler directly interpolates unsanitized content into generated code as an executable expression, and the quote filter does not strip backticks, allowing template literal-based payloads to bypass sanitization. Version 20.8.8 fixes the issue.

Published: 2026-03-27T21:15:19.186Z
Updated: 2026-07-15T01:05:08.620Z

In versions before 20.0.2, it was found that --disallow-code-generation-from-strings is not sufficient for isolating untrusted JavaScript in happy-dom. The untrusted script and the rest of the application still run in the same Isolate/process, so attackers can deploy prototype pollution payloads to hijack important references like "process" in the example below, or to hijack control flow via flipping checks of undefined property. This vulnerability is due to an incomplete fix for CVE-2025-61927. The vulnerability is fixed in 20.0.2.

Published: 2025-10-15T17:16:21.561Z
Updated: 2025-10-15T18:16:44.558Z

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.

Published: 2025-10-10T19:38:19.835Z
Updated: 2025-10-10T19:59:09.406Z

happy-dom is a JavaScript implementation of a web browser without its graphical user interface. Versions of happy-dom prior to 15.10.2 may execute code on the host via a script tag. This would execute code in the user context of happy-dom. Users are advised to upgrade to version 15.10.2. There are no known workarounds for this vulnerability.

Published: 2024-11-06T19:18:23.923Z
Updated: 2024-11-06T20:05:28.358Z