CVE-2026-118660: high-severity vulnerability in capricorn86 happy-dom
Happy DOM: SSRF via iframe and link stylesheet when parsing untrusted HTML
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.6epss 0.4%
Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. Prior to 21.0.0, Happy DOM loads iframe src URLs and link rel="stylesheet" href URLs by default while parsing untrusted HTML on the server because disableIframePageLoading and disableCSSFileLoading default to false. An attacker who controls parsed HTML can therefore cause server-side requests to arbitrary internal or cloud endpoints without an application opt-in and may expose confidential responses or credentials returned by those endpoints. This issue is fixed in version 21.0.0.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
Affected products
capricorn86 · happy-domRelated CVEs — capricorn86 happy-dom
In the same product, most dangerous first.
CVE-2024-51757CRITICALFixes security vulnerability that allowed for server side code to be executed by a <script> tagEPSS 0.8%CVE-2026-33943HIGHHappy DOM ECMAScriptModuleCompiler: unsanitized export names are interpolated as executable codeEPSS 0.6%CVE-2025-61927HIGHHappy-DOM has VM Context EscapeEPSS 0.6%CVE-2026-115895HIGHHappy DOM: Incomplete fix for CVE-2026-33943: unsanitized import alias leads to host code executionEPSS 0.5%CVE-2026-34226HIGHHappy DOM's fetch credentials include uses page-origin cookies instead of target-origin cookiesEPSS 0.5%CVE-2026-118659HIGH@happy-dom/server-renderer: ServerRendererServer Target-Origin Bypass SSRF / Open ProxyEPSS 0.4%