CVE-2026-111766
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.
How to fix
- markdown-it14.3.3, 15.0.3 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| markdown-itnpm | v < 14.3.3, 15.0.0 ≤ v < 15.0.3 | 14.3.3, 15.0.3 |
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Attack Surface Management
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