What is GHSA-4239-8pr8-4pwv?

GHSA-4239-8pr8-4pwv is a security advisory published by GitHub Security Advisories with High severity. Mistune from 3.0.0 before 3.3.0 contains an algorithmic complexity denial of service...

Which CVE IDs does GHSA-4239-8pr8-4pwv cover?

GHSA-4239-8pr8-4pwv covers the following CVE IDs: CVE-2026-115349. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of GHSA-4239-8pr8-4pwv?

GHSA-4239-8pr8-4pwv has a CVSS v3 base score of 7.5, published by GitHub Security Advisories.

GHSA-4239-8pr8-4pwvHighCVSS 7.5

Mistune from 3.0.0 before 3.3.0 contains an algorithmic complexity denial of service...

Vendor

GitHub Security Advisories

Published

October 22, 2026

Last Modified

October 22, 2026

🔗 CVE IDs covered (1)

CVE-2026-115349 →

📋 Description

Mistune from 3.0.0 before 3.3.0 contains an algorithmic complexity denial of service vulnerability in the parse_link_text function in src/mistune/helpers.py. Attackers can submit markdown with deeply nested square brackets triggering quadratic parsing time, exhausting server CPU with small crafted requests.

🔗 References (4)

https://github.com/lepture/mistune/security/advisories/GHSA-3q64-rw38-243v
https://nvd.nist.gov/vuln/detail/CVE-2026-115349
https://www.vulncheck.com/advisories/mistune-3.0.0-before-3.3.0-denial-of-service-via-nested-bracket-parsing
https://github.com/advisories/GHSA-4239-8pr8-4pwv