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CVE-2026-86430

CVE-2026-86430 · league/commonmark before 2.9.1 Denial of Service via parsing

This page contains facts from public vulnerability sources. Check the original advisory before updating.

league/commonmark versions before 2.9.1 contain multiple denial of service vulnerabilities in fenced code block detection, reference link label lookup, and emphasis delimiter processing that perform super-linear work on crafted input. Attackers can submit specially crafted Markdown with long backtick runs, nested brackets, or delimiter sequences to consume disproportionate CPU time and prevent legitimate requests from completing.

CVSS 8.7 · High · EPSS 0.5% · Fix available

Published
Updated

Stack: system · php

Affected products and versions

  • commonmark

    Versions
    • ≥ 0.6.0, < 2.9.1: Affected (semver)
    • 2.9.1: Not affected (semver)

    Update to 2.9.1

  • php-league-commonmark Debian:12

    Versions
    • 2.10.0-1
    • 2.10.1-1
    • 2.10.3-1
    • 2.3.9-1
    • 2.3.9-1+deb12u1
    • 2.4.0-1
    • 2.4.1-1
    • 2.4.2-1
    • 2.4.2-2
    • 2.5.0-1
    • 2.5.1-1
    • 2.5.3-1
    • 2.6.0-1
    • 2.6.1-1
    • 2.6.1-2
    • 2.6.2-1
    • 2.7.0-1
    • 2.7.1-1
    • 2.7.1-2
    • 2.8.0-1
    • 2.8.1-1
    • 2.8.2-1
    • 2.8.2-2
    • 2.8.3-1
    • 2.9.0-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • php-league-commonmark Debian:13

    Versions
    • 2.10.0-1
    • 2.10.1-1
    • 2.10.3-1
    • 2.7.0-1
    • 2.7.0-1+deb13u1
    • 2.7.1-1
    • 2.7.1-2
    • 2.8.0-1
    • 2.8.1-1
    • 2.8.2-1
    • 2.8.2-2
    • 2.8.3-1
    • 2.9.0-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • php-league-commonmark Debian:14

    Versions
    • 2.7.0-1
    • 2.7.1-1
    • 2.7.1-2
    • 2.8.0-1
    • 2.8.1-1
    • 2.8.2-1
    • 2.8.2-2
    • 2.8.3-1
    • 2.9.0-1
    Affected ranges
    • ECOSYSTEM: < 2.10.0-1

    Update to 2.10.0-1

  • league/commonmark Packagist

    Versions
    • 0.10.0
    • 0.11.0
    • 0.11.1
    • 0.11.2
    • 0.11.3
    • 0.12.0
    • 0.13.0
    • 0.13.1
    • 0.13.2
    • 0.13.3
    • 0.13.4
    • 0.14.0
    • 0.15.0
    • 0.15.1
    • 0.15.2
    • 0.15.3
    • 0.15.4
    • 0.15.5
    • 0.15.6
    • 0.15.7
    • 0.16.0
    • 0.17.0
    • 0.17.1
    • 0.17.2
    • 0.17.3
    • 0.17.4
    • 0.17.5
    • 0.18.0
    • 0.18.1
    • 0.18.2
    • 0.18.3
    • 0.18.4
    • 0.18.5
    • 0.19.0
    • 0.19.1
    • 0.19.2
    • 0.19.3
    • 0.6.0
    • 0.6.1
    • 0.7.0
    • 0.7.1
    • 0.7.2
    • 0.8.0
    • 0.9.0
    • 1.0.0
    • 1.0.0-beta1
    • 1.0.0-beta2
    • 1.0.0-beta3
    • 1.0.0-beta4
    • 1.0.0-rc1
    • 1.1.0
    • 1.1.1
    • 1.1.2
    • 1.1.3
    • 1.2.0
    • 1.2.1
    • 1.2.2
    • 1.3.0
    • 1.3.1
    • 1.3.2
    • 1.3.3
    • 1.3.4
    • 1.4.0
    • 1.4.1
    • 1.4.2
    • 1.4.3
    • 1.5.0
    • 1.5.1
    • 1.5.2
    • 1.5.3
    • 1.5.4
    • 1.5.5
    • 1.5.6
    • 1.5.7
    • 1.5.8
    • 1.6.0
    • 1.6.1
    • 1.6.2
    • 1.6.3
    • 1.6.4
    • 1.6.5
    • 1.6.6
    • 1.6.7
    • 2.0.0
    • 2.0.0-beta1
    • 2.0.0-beta2
    • 2.0.0-beta3
    • 2.0.0-rc1
    • 2.0.0-rc2
    • 2.0.1
    • 2.0.2
    • 2.0.3
    • 2.0.4
    • 2.1.0
    • 2.1.1
    • 2.1.2
    • 2.1.3
    • 2.2.0
    • 2.2.1
    • 2.2.2
    • 2.2.3
    • 2.2.4
    • 2.2.5
    • 2.3.0
    • 2.3.1
    • 2.3.2
    • 2.3.3
    • 2.3.4
    • 2.3.5
    • 2.3.6
    • 2.3.7
    • 2.3.8
    • 2.3.9
    • 2.4.0
    • 2.4.1
    • 2.4.2
    • 2.4.3
    • 2.4.4
    • 2.5.0
    • 2.5.1
    • 2.5.2
    • 2.5.3
    • 2.6.0
    • 2.6.1
    • 2.6.2
    • 2.7.0
    • 2.7.1
    • 2.8.0
    • 2.8.1
    • 2.8.2
    • 2.8.3
    • 2.9.0
    Affected ranges
    • ECOSYSTEM: ≥ 0.6.0, < 2.9.1

    Update to 2.9.1

  • php-league-commonmark Ubuntu:Pro:20.04:LTS

    Versions
    • 1.1.2-1
    • 1.2.0-1
    • 1.3.0-1
    • 1.3.1-1
    • 1.3.1-1ubuntu2
    • 1.3.1-1ubuntu2+esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • php-league-commonmark Ubuntu:Pro:22.04:LTS

    Versions
    • 1.5.7-2build1
    • 1.6.6-1build1
    • 1.6.7-1
    • 1.6.7-1ubuntu0.1~esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • php-league-commonmark Ubuntu:Pro:24.04:LTS

    Versions
    • 2.3.9-1
    • 2.4.1-1
    • 2.4.2-1
    • 2.4.2-2
    • 2.4.2-2ubuntu0.1~esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • php-league-commonmark Ubuntu:26.04:LTS

    Versions
    • 2.7.0-1
    • 2.7.1-2
    • 2.8.0-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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