{"apiVersion":"1.0","identifier":"CVE-2026-5751","description":"justhtml versions 1.13.0 and earlier contain a parser-differential / mutation cross-site scripting (mXSS) vulnerability when using a custom SanitizationPolicy that preserves foreign namespaces (e.g., drop_foreign_namespaces=False with allowlisted SVG/MathML elements or raw-text containers such as <style>). Specially crafted input can sanitize into markup that appears safe but becomes unsafe when re-parsed by a browser or another HTML parser, allowing markup injection. The default safe configuration (sanitize=True) is not affected. Fixed in 1.14.0.","publishedAt":"2026-08-23T14:16:53","lastModifiedAt":"2026-08-26T17:10:53","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-5751","cvssScore":6.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","epssProbability":0.00188,"riskScore":0.62,"affectedProduct":"justhtml","affectedVersions":"<=1.13.0","vulnerabilityType":"Library","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-5751","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-5751","en":"https://www.redsauce.net/en/cves/CVE-2026-5751","fr":"https://www.redsauce.net/fr/cves/CVE-2026-5751","pt":"https://www.redsauce.net/pt/cves/CVE-2026-5751","de":"https://www.redsauce.net/de/cves/CVE-2026-5751","sk":"https://www.redsauce.net/sk/cves/CVE-2026-5751","el":"https://www.redsauce.net/el/cves/CVE-2026-5751"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-5751"}}