CVE-2026-7808
justhtml HTML-sanitizer bypass allows XSS via malformed DOM, doctypes, SVG/MathML
Is CVE-2026-7808 being exploited?
Not confirmed. CVE-2026-7808 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.35% probability of exploitation in the next 30 days.
How severe is CVE-2026-7808?
CVE-2026-7808 is rated Critical with a CVSS score of 9.3. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-7808?
Yes. A fix has been recorded for CVE-2026-7808. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-7808 affect?
CVE-2026-7808 affects justhtml < 1.16.0, Web applications using justhtml for sanitization, Apps that reuse/export sanitizer policy objects. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-7808?
Upgrade justhtml to >=1.16.0; avoid mutating/exporting sanitizer policies; review sanitized inputs
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Cross-site scripting: attackers can inject/execute scripts/styles in users' browsers, enabling session theft, account takeover, or actions as victims.
Immediate action required
- affected< 1.16.0
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.