{"cve":"CVE-2026-111766","nvd":{"published":"2026-10-19T20:17:52.247","modified":"2026-10-19T21:13:39.973","status":"Awaiting Analysis","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","score":3.7},"cwes":["CWE-400","CWE-407"],"references":["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","https://github.com/markdown-it/markdown-it/security/advisories/GHSA-vfgh-jcmw-g37q"],"products":[],"source":"nvd","synced_at":"2026-10-21T03:56:58.798400159+00:00"},"epss":{"cve":"CVE-2026-111766","score":0.00428,"percentile":0.3675,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-vfgh-jcmw-g37q","url":"https://osv.dev/vulnerability/GHSA-vfgh-jcmw-g37q","summary":"markdown-it: Quadratic-time denial of service in inline HTML parsing with html enabled","modified":"2026-10-20T20:15:05.220039200Z","packages":[{"ecosystem":"npm","name":"markdown-it","purl":"pkg:npm/markdown-it","ranges":["<14.3.3"],"fixed":["14.3.3"]},{"ecosystem":"npm","name":"markdown-it","purl":"pkg:npm/markdown-it","ranges":[">=15.0.0 <15.0.3"],"fixed":["15.0.3"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}