CVE-2026-111766
Vulnérabilité faible dans markdown-it (markdown-it)
Description
markdown-it is a Markdown parser. Prior to 14.3.3 and 15.0.3, when the html option or commonmark preset is enabled and the constructs occur inside a paragraph, attacker-controlled Markdown containing repeated unterminated inline HTML comments, processing instructions, declarations, or CDATA sections reaches src/rules_inline/html_inline.ts. Its HTML_TAG_RE match searches the remaining suffix for the appropriate terminator; when no terminator is present, parsing advances to the next opener and repeats the match over overlapping input, causing quadratic processing and denial of service through event-loop blocking or an unresponsive browser main thread. HTML blocks and the default HTML-disabled configuration are not affected by these payloads. This issue is fixed in versions 14.3.3 and 15.0.3.
Gravité et risque d'exploitation
CVE-2026-111766 obtient un score CVSS de 3.7/10, soit une gravité faible.
Que faire ?
- Vérifiez si markdown-it (versions < 14.3.3, >= 15.0.0, < 15.0.3) est présent sur votre parc.
- Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
- À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
- Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.
Références
- https://github.com/markdown-it/markdown-it/security/advisories/GHSA-vfgh-jcmw-g37q
- https://github.com/markdown-it/markdown-it/commit/928bc8c11ded60181c0e7fc5aa954eec582e8e79
- https://github.com/markdown-it/markdown-it/commit/d99f48839d37af6fd8a2617516c43dab90755503
- https://github.com/markdown-it/markdown-it/releases/tag/14.3.3
- https://github.com/markdown-it/markdown-it/releases/tag/15.0.3
