Server-side Request Forgery (SSRF) Affecting happy-dom package, versions <21.0.0
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Start learning- Snyk IDSNYK-JS-HAPPYDOM-21826830
- published29 Oct 2026
- disclosed28 Oct 2026
- creditTharVid
Introduced: 28 Oct 2026
NewCVE-2026-118660 (opens in a new tab)How to fix?
Upgrade happy-dom to version 21.0.0 or higher.
Overview
happy-dom is a Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. It includes many web standards from WHATWG DOM and HTML.
Affected versions of this package are vulnerable to Server-side Request Forgery (SSRF) via automatic loading of external resources in HTMLIFrameElement and HTMLLinkElement. When a document containing an <iframe src="..."> or <link rel="stylesheet" href="..."> element is parsed, happy-dom issues real HTTP requests to the specified URLs without any user opt-in, allowing an attacker who controls the rendered HTML to cause the server running happy-dom to make arbitrary outbound requests - including to internal network endpoints such as cloud metadata services.