markdown-it: Quadratic-time rendering of a single multi-line link reference definition with default options (regression since 14.0)
Summary
| CVE | CVE-2026-111758 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_M |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-20 21:17:17 UTC |
| Updated | 2026-10-20 21:17:17 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v3.1 7.5 HIGH from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Problem Types: CWE-400 | CWE-407 | CWE-400 CWE-400: Uncontrolled Resource Consumption | CWE-407 CWE-407: Inefficient Algorithmic Complexity
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | CNA | DECLARED | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Markdown-it | Markdown-it | affected >= 14.1.0, < 14.3.3 | Not specified |
| CNA | Markdown-it | Markdown-it | affected >= 15.0.0, < 15.0.3 | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/markdown-it/markdown-it/releases/tag/15.0.3 | [email protected] | github.com | |
| github.com/markdown-it/markdown-it/releases/tag/14.3.3 | [email protected] | github.com | |
| github.com/markdown-it/markdown-it/commit/d99f48839d37af6fd8a2617516c43d... | [email protected] | github.com | |
| github.com/markdown-it/markdown-it/security/advisories/GHSA-gfr2-rv44-r23c | [email protected] | github.com | |
| github.com/markdown-it/markdown-it/commit/48fbc465812c440020c663f040ab22... | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.