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CVE-2026-71488

CVE-2026-71488 · league/commonmark: Quadratic-time denial of service when parsing crafted Markdown

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

league/commonmark is a PHP library for parsing and rendering CommonMark Markdown. From 0.6.0 until 2.9.0, specially crafted Markdown lines can cause the parser to have quadratic time complexity when converting, because several parsing paths repeatedly rescan growing portions of a line to translate between character positions and byte positions, and the Autolink extension can also copy and validate the remaining line at every URL-like prefix, allowing an attacker who can submit Markdown for conversion to consume disproportionate CPU time with a comparatively small request. This issue is fixed in 2.9.0.

CVSS 7.5 · High · EPSS 0.6% · Fix available

Published
Updated

Stack: system · php

Affected products and versions

  • commonmark

    Versions
    • >= 0.6.0, < 2.9.0: Affected

    No fix published

  • php-league-commonmark Debian:12

    Versions
    • 2.10.0-1
    • 2.10.1-1
    • 2.10.3-1
    • 2.10.4-1
    • 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
    • 2.10.4-1
    • 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
    Affected ranges
    • ECOSYSTEM: < 2.9.0-1

    Update to 2.9.0-1

  • 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
    Affected ranges
    • ECOSYSTEM: ≥ 0.6.0, < 2.9.0

    Update to 2.9.0

  • markdown Ubuntu:16.04:LTS

    Versions
    • 1.0.1-7
    • 1.0.1-8
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • markdown Ubuntu:18.04:LTS

    Versions
    • 1.0.1-9
    • 1.0.1-10
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • markdown Ubuntu:20.04:LTS

    Versions
    • 1.0.1-10
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • commonmark Ubuntu:22.04:LTS

    Versions
    • 0.9.1-3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • markdown Ubuntu:22.04:LTS

    Versions
    • 1.0.1-10.1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • commonmark Ubuntu:24.04:LTS

    Versions
    • 0.9.1-4
    • 0.9.1-5
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • markdown Ubuntu:24.04:LTS

    Versions
    • 1.0.1-12
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • commonmark Ubuntu:26.10

    Versions
    • 0.9.1-8build1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • markdown Ubuntu:26.10

    Versions
    • 1.0.1-14
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • commonmark Ubuntu:26.04:LTS

    Versions
    • 0.9.1-8
    • 0.9.1-8build1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • markdown Ubuntu:26.04:LTS

    Versions
    • 1.0.1-14
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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