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CVE-2026-111758GHSA-GFR2-RV44-R23C

markdown-it: Quadratic-time rendering of a single multi-line link reference definition with default options (regression since 14.0)

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 14.3.3, 15.0.3
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: poc
  • Automatable: yes
  • Technical impact: partial

Summary

markdown-it is a Markdown parser. From versions 14.1.0 to before 14.3.3, and 15.0.0 to before 15.0.3, a link reference definition whose label or title is never closed is O(n²) with default options. Continuation lines are pulled lazily with str += lineContent in src/rules_block/reference.ts, and the subsequent charCodeAt and slice calls flatten the V8 cons-string, copying everything collected so far; this runs before the rule decides the definition is invalid. No options are required to trigger it. This issue has been patched in versions 14.3.3 and 15.0.3.

Timeline

  1. CVE published
  2. First seen by cve.now
  3. CISA SSVC assessment

    Exploitation: poc · Automatable: yes · Technical impact: partial

  4. Record last updated

Affected versions

  • markdown-it markdown-it

    From 14.1.0 · fixed in 14.3.3; From 15.0.0 · fixed in 15.0.3

  • markdown-itnpm

    From 14.1.0 · fixed in 14.3.3

  • markdown-itnpm

    From 15.0.0 · fixed in 15.0.3

References 5

GitHub · markdown-it/markdown-it