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.
{
"cna_assigner": "GitHub_M",
"cwe_ids": [
"CWE-918"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/118xxx/CVE-2026-118660.json"
}{
"extracted_events": [
{
"range": [
{
"introduced": "0"
},
{
"fixed": "21.0.0"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StringRangeExpression"
},
{
"range": [
{
"fixed": "0a99c7525a1d0043e3182843ae33466ab7b19e74"
}
],
"source": "REFERENCES_COMMIT"
},
{
"original_tag": "v21.0.0",
"range": [
{
"fixed": "0a99c7525a1d0043e3182843ae33466ab7b19e74"
}
],
"source": "REFERENCES_TAG"
}
]
}