--- title: "CVE-2026-118660: Happy DOM - Server Side Request Forgery" description: "Happy DOM < 21.0.0 contains a server-side request forgery caused by default loading of iframe src and stylesheet href URLs during HTML parsing, letting attackers cause server-side requests to arbitrary endpoints, exploit requires control of parsed HTML." url: https://panop.io/threat-heartbeat/CVE-2026-118660/ --- # CVE-2026-118660 Happy DOM - Server Side Request Forgery Happy DOM < 21.0.0 contains a server-side request forgery caused by default loading of iframe src and stylesheet href URLs during HTML parsing, letting attackers cause server-side requests to arbitrary endpoints, exploit requires control of parsed HTML. CVSS base score 8.6 /10 High CISA KEV Not listed Public exploit None known Authentication Not required [View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-118660) ## Details Type Server Side Request Forgery Impact Information Disclosure CVSS vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N Published 28 October 2026 Updated 29 October 2026 Weakness [CWE-918](https://cwe.mitre.org/data/definitions/918.html) ## Vendor fix Update to version 21.0.0 or later. Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them. ## References - [https://nvd.nist.gov/vuln/detail/CVE-2026-118660](https://nvd.nist.gov/vuln/detail/CVE-2026-118660) - [https://github.com/capricorn86/happy-dom/security/advisories/GHSA-c8p4-j97h-3vg8](https://github.com/capricorn86/happy-dom/security/advisories/GHSA-c8p4-j97h-3vg8) - [https://github.com/capricorn86/happy-dom/commit/0a99c7525a1d0043e3182843ae33466ab7b19e74](https://github.com/capricorn86/happy-dom/commit/0a99c7525a1d0043e3182843ae33466ab7b19e74) - [https://github.com/capricorn86/happy-dom/pull/2502](https://github.com/capricorn86/happy-dom/pull/2502) - [https://github.com/capricorn86/happy-dom/releases/tag/v21.0.0](https://github.com/capricorn86/happy-dom/releases/tag/v21.0.0) [← All CVEs](https://panop.io/threat-heartbeat/) ## What this record can't tell you - Whether you run the affected software, and where - Whether an attacker can actually reach and exploit it - The misconfigurations that never get a CVE number - What it would cost the business, ranked into what to fix first Panop answers these inside your environment, for this CVE and every other finding. [Book a demo](https://panop.io/demo)