Algorithmic Complexity Affecting php-league-commonmark package, versions <2.9.0-1


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
0.49% (40th percentile)

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  • Snyk IDSNYK-DEBIAN14-PHPLEAGUECOMMONMARK-19641652
  • published8 Sept 2026
  • disclosed7 Sept 2026

Introduced: 7 Sep 2026

CVE-2026-86435  (opens in a new tab)
CWE-407  (opens in a new tab)

How to fix?

Upgrade Debian:14 php-league-commonmark to version 2.9.0-1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream php-league-commonmark package and not the php-league-commonmark package as distributed by Debian. See How to fix? for Debian:14 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1