{"id":"CVE-2026-118660","sourceIdentifier":"security-advisories@github.com","published":"2026-10-28T21:16:56.123","lastModified":"2026-10-29T18:17:27.943","vulnStatus":"Awaiting Analysis","cveTags":[],"descriptions":[{"lang":"en","value":"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."}],"affected":[{"source":"security-advisories@github.com","affectedData":[{"vendor":"capricorn86","product":"happy-dom","versions":[{"version":"< 21.0.0","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N","baseScore":8.6,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"HIGH","integrityImpact":"NONE","availabilityImpact":"NONE"},"exploitabilityScore":3.9,"impactScore":4.0}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-10-29T15:43:35.972529Z","id":"CVE-2026-118660","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-918"}]}],"references":[{"url":"https://github.com/capricorn86/happy-dom/commit/0a99c7525a1d0043e3182843ae33466ab7b19e74","source":"security-advisories@github.com"},{"url":"https://github.com/capricorn86/happy-dom/pull/2502","source":"security-advisories@github.com"},{"url":"https://github.com/capricorn86/happy-dom/releases/tag/v21.0.0","source":"security-advisories@github.com"},{"url":"https://github.com/capricorn86/happy-dom/security/advisories/GHSA-c8p4-j97h-3vg8","source":"security-advisories@github.com"}]}