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.

Quick Facts

References

• https://github.com/markdown-it/markdown-it/commit/928bc8c11d…
• https://github.com/markdown-it/markdown-it/commit/d99f48839d…
• https://github.com/markdown-it/markdown-it/releases/tag/14.3…
• https://github.com/markdown-it/markdown-it/releases/tag/15.0…
• https://github.com/markdown-it/markdown-it/security/advisori…

External Resources