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CVE-2026-71478

CVE-2026-71478 · league/commonmark: AttributesExtension href/src unsafe-link filter bypass via embedded control bytes

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 1.5.0 until 2.9.0, the AttributesExtension's href and src unsafe-link filter can be bypassed by embedding control bytes, such as a tab, carriage return, line feed, or leading C0 control character, in a javascript: URL that browsers discard before parsing the scheme, causing the browser to still execute the script even when the unsafe-link filter is enabled. This issue is fixed in 2.9.0.

CVSS 6.1 · Medium · EPSS 0.4% · Fix available

Published
Updated

Stack: system · php

Affected products and versions

  • commonmark

    Versions
    • >= 1.5.0, <= 2.8.3: 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
    • 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: ≥ 1.5.0, < 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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