Server-side Request Forgery (SSRF) Affecting @happy-dom/server-renderer package, versions <21.0.2
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-HAPPYDOMSERVERRENDERER-21826827
- published29 Oct 2026
- disclosed28 Oct 2026
- creditEQSTLab
Introduced: 28 Oct 2026
NewCVE-2026-118659 (opens in a new tab)How to fix?
Upgrade @happy-dom/server-renderer to version 21.0.2 or higher.
Overview
@happy-dom/server-renderer is an Use Happy DOM for server-side rendering (SSR) or as a static site generator (SSG).
Affected versions of this package are vulnerable to Server-side Request Forgery (SSRF) via the proxy request handler in ServerRendererServer.ts, where the constructed URL is not validated against the configured targetOrigin before being fetched. An attacker can supply a protocol-relative URL (e.g. //attacker-host/path) as the request path, causing new URL(request.url, targetOrigin) to resolve to an entirely different origin, bypassing the intended restriction and allowing the proxy to fetch arbitrary internal or external resources. The fix adds an explicit origin comparison after URL construction and enforces the same check on each redirect hop.