CVE-2026-111758

HIGH
MEDIUM Priority: 0.04 BB Relevance: 75/100
Published: 2026-10-20 Modified: 2026-10-28 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Auth No Interaction

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: None
S: Unchanged
C: None
I: None
A: High

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.

Weakness Classification (2)

Affected Software (1)

VendorProductVersion
markdown-it markdown-it >= 14.1.0, < 14.3.3

Bug Bounty Relevance

75 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

7.5 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploitation Probability

0.55%
Raw Score 0.005500
Percentile 46.0%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00550
2026-10-28
0.00455

Intelligence Sources

mitre ref →
nvd ref →