SB2026110604 - Inefficient regular expression complexity in markdown-it
Published: November 6, 2026
Security Bulletin ID
SB2026110604
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Partial DoS
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Inefficient regular expression complexity (CVE-ID: CVE-2026-2327)
CWE-ID: CWE-1333 - Inefficient Regular Expression Complexity
CVSSv4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to the use of the regex /*+$/ in the linkify function. A remote attacker can supply a long sequence of * characters followed by a non-matching character, which triggers excessive backtracking and may lead to a denial-of-service condition.
Remediation
Install update from vendor's website.
References
- https://gist.github.com/ltduc147/c9abecae1b291ede4f692f2ab988c917
- https://github.com/markdown-it/markdown-it/blob/14.1.0/lib/rules_inline/linkify.mjs%23L33
- https://github.com/markdown-it/markdown-it/commit/4b4bbcae5e0990a5b172378e507b33a59012ed26
- https://security.snyk.io/vuln/SNYK-JS-MARKDOWNIT-10666750