GHSA-rmmh-p597-ppvv

Showdown vulnerable to Regular Expression Denial of Service (ReDoS) in link/anchor parsing

Source: GitHub Advisory Database (reviewed) Moderate CVE-2024-1899

Packages

Ecosystem	Package	Affected	Fixed in
npm	showdown	<= 2.1.0	no fix listed

Details

As written in the advisory (Markdown source, shown as plain text).

Showdownjs, versions <= 2.1.0, `anchors` subparser used to parse links has a nested regular expression which can lead to denial of service conditions given malicious input.

References

External links from the advisory. They lead to third-party sites.

https://nvd.nist.gov/vuln/detail/CVE-2024-1899 advisory
https://github.com/showdownjs/showdown package
https://www.tenable.com/security/research/tra-2024-05 web