SB2026090265 - Inefficient Algorithmic Complexity in markdown-it

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Main Vulnerability Database SB2026090265

SB2026090265 - Inefficient Algorithmic Complexity in markdown-it

Published: September 2, 2026

Security Bulletin ID SB2026090265
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Inefficient Algorithmic Complexity (CVE-ID: N/A)

CWE-ID: CWE-407 - Inefficient Algorithmic Complexity

CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to inefficient algorithmic complexity in linkify handling when parsing crafted markdown input with linkify: true. A remote attacker can send specially crafted markdown content to cause a denial of service.

Only applications that enable the linkify option are vulnerable. The issue is availability-only and can block the event loop for tens of seconds with a few hundred kilobytes of ordinary-looking markdown.


Remediation

Install update from vendor's website.

References