DOMSanitizer is a DOM/SVG/MathML Sanitizer for PHP 7.3+. Prior to version 1.0.15, the isDangerousUrl() method is responsible for rejecting dangerous URL values in the href and xlink:href attributes. The weakness is that "javascript:" is rejected as a scheme, while "data:" is rejected only when the literal substring onload appears in the URL value (/^data:.*onload/i). Because data: payloads are routinely Base64-encoded, the dangerous content (
{
"cna_assigner": "GitHub_M",
"cwe_ids": [
"CWE-20"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/100xxx/CVE-2026-100370.json"
}{
"extracted_events": [
{
"range": [
{
"introduced": "0"
},
{
"fixed": "1.0.15"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StringRangeExpression"
},
{
"range": [
{
"fixed": "10f97807e4501d60f63987f2e76a38cdbf312dcb"
}
],
"source": "REFERENCES_COMMIT"
},
{
"range": [
{
"fixed": "fb8f758b41134fc5fb2f563666f2330c69e31f94"
}
],
"source": "REFERENCES_COMMIT"
},
{
"original_tag": "1.0.15",
"range": [
{
"fixed": "10f97807e4501d60f63987f2e76a38cdbf312dcb"
}
],
"source": "REFERENCES_TAG"
}
]
}