CVE-2026-8445
justhtml to_markdown() allows sanitizer bypass leading to XSS in rendered Markdown.
Is CVE-2026-8445 being exploited?
Not confirmed. CVE-2026-8445 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 0.38% probability of exploitation in the next 30 days.
How severe is CVE-2026-8445?
CVE-2026-8445 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-2026-8445?
Yes. A fix has been recorded for CVE-2026-8445. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-8445 affect?
CVE-2026-8445 affects justhtml <= 1.11.0, Apps using justhtml.to_markdown() to convert HTML to Markdown. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-8445?
Upgrade to justhtml 1.12.0 and sanitize/encode untrusted input before conversion.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Sanitizer bypass: untrusted HTML (e.g., <script>) can be emitted in Markdown output, enabling stored/reflected XSS and remote script execution when rendered.
Immediate action required
- affected< 1.12.0
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.