CVE-2026-118661
Dashboard / Vulnerabilities / CVE-2026-118661
Summary: Happy DOM: Cookie scope forgery: no DNS-label boundary on Domain= matching , attacker origin sets victim cookies
Details: 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.
References: https://github.com/capricorn86/happy-dom/releases/tag/v20.14.6, https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/118xxx/CVE-2026-118661.json, https://github.com/capricorn86/happy-dom/security/advisories/GHSA-5fpq-26gf-qwcr, https://nvd.nist.gov/vuln/detail/CVE-2026-118661, https://github.com/capricorn86/happy-dom/commit/f21dbd7d0a0c63cdd41954ba5d0f05def4e0f2b3, https://github.com/capricorn86/happy-dom/pull/2477
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