{"id":"CVE-2026-118661","sourceIdentifier":"security-advisories@github.com","published":"2026-10-28T21:16:56.267","lastModified":"2026-11-03T14:17:31.910","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 20.14.6, Happy DOM's CookieContainer in src/cookie/CookieContainer.ts does not correctly validate or match Domain cookie attributes. It can accept a Domain unrelated to the origin setting the cookie, including a public suffix, and separately treats an unrelated suffix-sharing hostname as a match because cookieMatchesURL does not enforce a DNS-label boundary. In server-side rendering and prerendering applications that contact attacker-controlled origins and then make requests to a victim origin, these behaviors can plant and deliver a forged cookie, enabling cookie injection or session fixation. This issue is fixed in version 20.14.6."}],"affected":[{"source":"security-advisories@github.com","affectedData":[{"vendor":"capricorn86","product":"happy-dom","versions":[{"version":"< 20.14.6","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:U/C:L/I:L/A:N","baseScore":6.5,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"NONE"},"exploitabilityScore":3.9,"impactScore":2.5}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-11-03T13:33:09.550280Z","id":"CVE-2026-118661","options":[{"exploitation":"poc"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-565"}]}],"references":[{"url":"https://github.com/capricorn86/happy-dom/commit/f21dbd7d0a0c63cdd41954ba5d0f05def4e0f2b3","source":"security-advisories@github.com"},{"url":"https://github.com/capricorn86/happy-dom/pull/2477","source":"security-advisories@github.com"},{"url":"https://github.com/capricorn86/happy-dom/releases/tag/v20.14.6","source":"security-advisories@github.com"},{"url":"https://github.com/capricorn86/happy-dom/security/advisories/GHSA-5fpq-26gf-qwcr","source":"security-advisories@github.com"},{"url":"https://github.com/capricorn86/happy-dom/security/advisories/GHSA-5fpq-26gf-qwcr","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}]}