Security Advisory

CVE-2026-86435

CVSS 7.5
HIGH

Vulnerability Description

commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Footnote extension that fails to deduplicate footnote definitions. Attackers can craft documents with duplicate footnote definitions and references to create quadratic output expansion, consuming excessive memory and CPU to exhaust server resources.
Published Date 2026-09-07T13:20:43.013
Data Feed NIST National Vulnerability Database