{"id":"CVE-2026-100370","summary":"DOMSanitizer - Incomplete data: URL Sanitization in DOMSanitizer::isDangerousUrl() Allows Base64-Encoded Payloads to Bypass href and xlink:href Validation","details":"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 (\u003cscript\u003e, event handlers, etc.) is invisible to that substring test. A URL such as data:text/html;base64,… therefore survives in href / xlink:href, even though the decoded payload is active markup. This is an incomplete input-validation / sanitization defect in the sanitizer itself. This issue has been patched in version 1.0.15.","aliases":["GHSA-wcj2-r6vg-rm97"],"modified":"2026-09-30T03:45:48.062564547Z","published":"2026-09-28T20:07:09.470Z","database_specific":{"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"},"references":[{"type":"WEB","url":"https://github.com/rhukster/dom-sanitizer/releases/tag/1.0.15"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/100xxx/CVE-2026-100370.json"},{"type":"ADVISORY","url":"https://github.com/rhukster/dom-sanitizer/security/advisories/GHSA-wcj2-r6vg-rm97"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-100370"},{"type":"FIX","url":"https://github.com/rhukster/dom-sanitizer/commit/10f97807e4501d60f63987f2e76a38cdbf312dcb"},{"type":"FIX","url":"https://github.com/rhukster/dom-sanitizer/commit/fb8f758b41134fc5fb2f563666f2330c69e31f94"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/rhukster/dom-sanitizer","events":[{"introduced":"0"},{"fixed":"10f97807e4501d60f63987f2e76a38cdbf312dcb"},{"fixed":"fb8f758b41134fc5fb2f563666f2330c69e31f94"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"1.0.15"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["1.0.14","1","1.0.13","1.0.12","1.0.11","1.0.10","1.0.9","1.0.8","1.0.7","1.0.6","1.0.5","1.0.4","1.0.3","1.0.2","1.0.1","1.0.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-100370.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N"}]}