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.
History

Fri, 30 Oct 2026 12:30:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Moderate


Thu, 29 Oct 2026 18:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 28 Oct 2026 22:15:00 +0000

Type Values Removed Values Added
First Time appeared Capricorn86
Capricorn86 happy-dom
Vendors & Products Capricorn86
Capricorn86 happy-dom

Wed, 28 Oct 2026 20:30:00 +0000

Type Values Removed Values Added
Description 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.
Title Happy DOM: SSRF via iframe and link stylesheet when parsing untrusted HTML
Weaknesses CWE-918
References
Metrics cvssV3_1

{'score': 8.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-10-28T20:23:10.122Z

Updated: 2026-10-29T17:23:32.163Z

Reserved: 2026-10-28T17:25:37.561Z

Link: CVE-2026-118660

cve-icon Vulnrichment

Updated: 2026-10-29T15:43:36.993Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-28T21:16:56.123

Modified: 2026-10-29T18:17:27.943

Link: CVE-2026-118660

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-10-28T20:23:10Z

Links: CVE-2026-118660 - Bugzilla