CVE-2026-111758markdown-it: Quadratic-time rendering of a single multi-line link reference definition with default options (regression since 14.0)
Updated under an hour ago ()
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It affects markdown-it. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- CWE-400, CWE-407
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- GitHub_M
- NVD analysis
- Received
- Record last updated
- Oct 20, 2026
- First seen by InfoSec Signals
- Oct 20, 2026
Affected products
markdown-it markdown-it markdown_it:markdown_it (from the name) | from 14.1.0, < 14.3.3; from 15.0.0, < 15.0.3 | CNA record |
References
- https://github.com/markdown-it/markdown-it/security/advisories/GHSA-gfr2-rv44-r23cx-refsource-confirm
- https://github.com/markdown-it/markdown-it/commit/48fbc465812c440020c663f040ab22deaf8f1ecax-refsource-misc
- https://github.com/markdown-it/markdown-it/commit/d99f48839d37af6fd8a2617516c43dab90755503x-refsource-misc
- https://github.com/markdown-it/markdown-it/releases/tag/14.3.3x-refsource-misc
- https://github.com/markdown-it/markdown-it/releases/tag/15.0.3x-refsource-misc
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.