Answer in brief
CVE-2026-111758 records a High severity (CVSS 7.5) vulnerability in markdown-it: Quadratic-time rendering of a single multi-line link reference definition with default options (regression since 14.0). The current sources do not mark it as known exploited. The current feed maps markdown-it/markdown-it (generic), markdown-it (npm), markdown-it (npm). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps markdown-it/markdown-it (generic), markdown-it (npm), markdown-it (npm). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| markdown-it/markdown-itgeneric | >=14.1.0 <14.3.3 || >=15.0.0 <15.0.3 | 14.3.3, 15.0.3 |
| markdown-itnpm | >=14.1.0,<14.3.3 | 14.3.3 |
| markdown-itnpm | >=15.0.0,<15.0.3 | 15.0.3 |
Published upstream
Oct 20, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 20, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 20, 2026
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.
Quoted source text, attributed separately from HOL analysis.