CVE-2026-118660: Happy DOM: SSRF via iframe and link stylesheet when parsing untrusted HTML
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.
References
- github.com/advisories/GHSA-c8p4-j97h-3vg8
- github.com/capricorn86/happy-dom/commit/0a99c7525a1d0043e3182843ae33466ab7b19e74
- github.com/capricorn86/happy-dom/pull/2502
- github.com/capricorn86/happy-dom/releases/tag/v21.0.0
- github.com/capricorn86/happy-dom/security/advisories/GHSA-c8p4-j97h-3vg8
- nvd.nist.gov/vuln/detail/CVE-2026-118660
Code Behaviors & Features
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