happy-dom

### Summary A cookie-scoping bug in happy-dom lets an attacker origin set cookies that a victim origin then receives, diverging from browser semantics. ### Details happy-dom matches Domain=example.com against notexample.com (endsWith without a DNS-label boundary), diverging from browser semantics (verified 20.11.6 npm latest: cookieMatchesURL(Domain=example.com, url=http://notexample.com) = true). Relevant where happy-dom is used for SSR/prerender cookie handling. Matching in src/cookie/CookieContainer.ts. ### PoC Run: ```bash node poc-happydom-cookie-domain.js ``` Full proof-of-concept so

CVE: CVE-2026-118661

## Summary happy-dom v20.8.9 makes real server-side HTTP requests to arbitrary URLs when parsing HTML containing `<iframe>` or `<link rel="stylesheet">` elements. This behavior is enabled by default (`disableIframePageLoading: false`, `disableCSSFileLoading: false`). When an application uses happy-dom to parse untrusted HTML on the server side, an attacker can trigger Server-Side Request Forgery by embedding these elements. ## Affected Versions - happy-dom <= 20.8.9 (latest) ## Vulnerable Behavior By default, happy-dom has: - `disableIframePageLoading: false` — iframes fetch their `src` URL

CVE: CVE-2026-118660

## Summary The ESM compiler in `happy-dom@20.14.5` does not validate imported local binding aliases before interpolating them into generated JavaScript. As a result, an invalid ESM import alias can be transformed into a valid JavaScript destructuring default initializer and executed. This appears to be an alternate injection path and incomplete remediation of GHSA-6q6h-j7hj-3r64 / CVE-2026-33943. The previous fix validates `importName` in the local `export { ... }` handler, but the named import handler still places an unvalidated `alias` directly into code context. These issues were confir

CVE: CVE-2026-115895

### Summary `happy-dom` 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. ### Details In [`packages/happy-dom/src/fetch/utilities/FetchRequestHeaderUtility.ts`](https://github.com/capricorn86/happy-dom/blob/f8d8cad41e9722fab9eefb9dfb3cca696462e908/packages/happy-dom/src/fetch/utilities/FetchRequestHeaderUtility.ts) (`getRequestHeaders()`), cookie selection is performed with `originURL`: ```ts const originURL = new URL(options.window.

CVE: CVE-2026-34226

### Summary 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. ### Details **Vulnerable file**: `packages/happy-dom/src/module/ECMAScriptModuleCompiler.ts`, lines 371-385 The "Export objec

CVE: CVE-2026-33943

### Summary The mitigation proposed in GHSA-37j7-fg3j-429f for disabling eval/Function when executing untrusted code in happy-dom does not suffice, since it still allows prototype pollution payloads. ### Details 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. There might be other payloads that allow the manipulation of require, e.g., via (univeral) gadgets (https

CVE: CVE-2025-62410

# Escape of VM Context gives access to process level functionality ## Summary 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 impor

CVE: CVE-2025-61927

### Impact Consumers of the NPM package `happy-dom` ### Patches The security vulnerability has been patched in v15.10.2 ### Workarounds No easy workarounds to my knowledge ### References [#1585](https://github.com/capricorn86/happy-dom/issues/1585)

CVE: CVE-2024-51757