CVE-2026-86435
HIGH
NVD
CVSS Score
7.5
Severity
HIGH
Published
Sep 07, 2026
Vendor
unknown
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.