All vulnerabilities
CVE-2026-118660GHSA-c8p4-j97h-3vg8

happy-dom: Happy DOM: SSRF via iframe and link stylesheet when parsing untrusted HTML

capricorn86 happy-dom
Open in ThreatlineRecord JSON
CVSS
8.6High
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)No scoreNo FIRST EPSS score in this snapshot yet
Fixed inNone listedNo source names a fixed version. Check the vendor advisory below
Published28 Oct 2026Updated 28 Oct 2026CVE List

What fixes it

No source in this snapshot names a fixed version. The vendor advisories under References are the place to check.

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.

Text from CVE List

Affected versions 1

  • happy-domaffected: < 21.0.0CVE List

References 4