CVE-2026-118659 @happy-dom/server-renderer: ServerRendererServer Target-Origin Bypass SSRF / Open Proxy
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-118659?
CVE-2026-118659 is a high-severity vulnerability in capricorn86 happy-dom, published on 28 Oct 2026.
Official description
Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. Prior to 21.0.2, the Happy DOM server-renderer package's ServerRendererServer accepts unauthenticated HTTP/2 requests and resolves attacker-controlled :path values against server.targetOrigin in #onIncomingRequest in packages/@happy-dom/server-renderer/src/ServerRendererServer.ts without confirming that the resolved origin remains trusted before calling fetch. A protocol-relative path can change the destination to an arbitrary HTTP or HTTPS endpoint reachable by the server, including local and internal services, and the proxy relays the fetched response headers and body to the requester. This issue is fixed in version 21.0.2.
Weakness: CWE-918
Which versions are affected by CVE-2026-118659?
How do I fix CVE-2026-118659?
No fix has been published for CVE-2026-118659 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-118659 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-118659 exists.
Sources
Also known as GHSA-pmf4-3xr3-xjhg.