{"id":"CVE-2026-100370","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-100370","generatedAt":"2026-10-28T00:57:20.687Z","title":"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).","description":"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 (<script>, 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.","published":"2026-09-28T21:17:10.000Z","lastModified":"2026-09-30T19:57:08.000Z","status":"Deferred","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":4.7,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N"},"cwe":["CWE-20"],"affected":[],"epss":{"score":0.00274,"percentile":0.19598,"date":"2026-10-26","history":[{"date":"2026-09-29","score":0.00274,"percentile":0.17789}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.27%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-09-28T21:17:10.000Z","detail":{"score":"4.7","severity":"MEDIUM","publishedAt":"2026-09-28T21:17:10.280Z"},"summary":"New CVE, medium severity (CVSS 4.7)."}],"references":[{"url":"https://github.com/rhukster/dom-sanitizer/commit/10f97807e4501d60f63987f2e76a38cdbf312dcb","source":"security-advisories@github.com"},{"url":"https://github.com/rhukster/dom-sanitizer/commit/fb8f758b41134fc5fb2f563666f2330c69e31f94","source":"security-advisories@github.com"},{"url":"https://github.com/rhukster/dom-sanitizer/releases/tag/1.0.15","source":"security-advisories@github.com"},{"url":"https://github.com/rhukster/dom-sanitizer/security/advisories/GHSA-wcj2-r6vg-rm97","source":"security-advisories@github.com"},{"url":"https://github.com/rhukster/dom-sanitizer/security/advisories/GHSA-wcj2-r6vg-rm97","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-100370","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}