{"id":"CVE-2026-111766","published":"2026-10-19T20:17:52.247","lastModified":"2026-10-19T21:13:39.973","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.","cvssScore":3.7,"cvssSeverity":"LOW","cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","cwes":["CWE-400","CWE-407"],"vendors":[],"products":[],"references":[{"url":"https://github.com/markdown-it/markdown-it/commit/928bc8c11ded60181c0e7fc5aa954eec582e8e79","tags":[]},{"url":"https://github.com/markdown-it/markdown-it/commit/d99f48839d37af6fd8a2617516c43dab90755503","tags":[]},{"url":"https://github.com/markdown-it/markdown-it/releases/tag/14.3.3","tags":[]},{"url":"https://github.com/markdown-it/markdown-it/releases/tag/15.0.3","tags":[]},{"url":"https://github.com/markdown-it/markdown-it/security/advisories/GHSA-vfgh-jcmw-g37q","tags":[]}],"exploitRefs":[{"url":"https://github.com/markdown-it/markdown-it/commit/928bc8c11ded60181c0e7fc5aa954eec582e8e79","tags":[]},{"url":"https://github.com/markdown-it/markdown-it/commit/d99f48839d37af6fd8a2617516c43dab90755503","tags":[]},{"url":"https://github.com/markdown-it/markdown-it/releases/tag/14.3.3","tags":[]},{"url":"https://github.com/markdown-it/markdown-it/releases/tag/15.0.3","tags":[]},{"url":"https://github.com/markdown-it/markdown-it/security/advisories/GHSA-vfgh-jcmw-g37q","tags":[]}],"hasPoc":true,"ai":null}