{"apiVersion":"1.0","identifier":"CVE-2026-6827","description":"justhtml before 1.17.0 contains multiple security issues in sanitization, serialization, and programmatic DOM handling. When custom policies preserve foreign namespaces (SVG/MathML), dangerous content such as HTML integration points (SVG <foreignObject>, MathML <annotation-xml encoding=-text/html->) and mutation-XSS parser-differential payloads could survive sanitization and become active HTML after reparse; SVG filter=-url(...)- and preserved <style> could leave resource-loading CSS (@import, background-image:url()). Programmatic script/style/Comment nodes could serialize into active markup. Additional hardening fixes address sanitize-pipeline cache mutation and DOM parent/child cycles that could cause infinite loops. Most issues affect advanced or custom configurations rather than the default JustHTML(..., sanitize=True) safe path.","publishedAt":"2026-08-23T14:16:53","lastModifiedAt":"2026-08-26T19:16:55","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-6827","cvssScore":6.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","epssProbability":0.00187,"riskScore":0.62,"affectedProduct":"justhtml","affectedVersions":"<1.17.0","vulnerabilityType":"Library","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-6827","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-6827","en":"https://www.redsauce.net/en/cves/CVE-2026-6827","fr":"https://www.redsauce.net/fr/cves/CVE-2026-6827","pt":"https://www.redsauce.net/pt/cves/CVE-2026-6827","de":"https://www.redsauce.net/de/cves/CVE-2026-6827","sk":"https://www.redsauce.net/sk/cves/CVE-2026-6827","el":"https://www.redsauce.net/el/cves/CVE-2026-6827"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-6827"}}