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CVE-2026-33347

CVE-2026-33347 · league/commonmark has an embed extension allowed_domains bypass

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

league/commonmark is a PHP Markdown parser. From version 2.3.0 to before version 2.8.2, the DomainFilteringAdapter in the Embed extension is vulnerable to an allowlist bypass due to a missing hostname boundary assertion in the domain-matching regex. An attacker-controlled domain like youtube.com.evil passes the allowlist check when youtube.com is an allowed domain. This issue has been patched in version 2.8.2.

CVSS 6.3 · Medium · EPSS 0.3% · Fix available

Published
Updated

Stack: system · php

Affected products and versions

  • commonmark

    Versions
    • >= 2.3.0, < 2.8.2: Affected

    No fix published

  • php-league-commonmark Debian:12

    Versions
    • 2.3.9-1
    Affected ranges
    • ECOSYSTEM: < 2.3.9-1+deb12u1

    Update to 2.3.9-1+deb12u1

  • php-league-commonmark Debian:13

    Versions
    • 2.7.0-1
    Affected ranges
    • ECOSYSTEM: < 2.7.0-1+deb13u1

    Update to 2.7.0-1+deb13u1

  • 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
    Affected ranges
    • ECOSYSTEM: < 2.8.2-1

    Update to 2.8.2-1

  • league/commonmark Packagist

    Versions
    • 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
    Affected ranges
    • ECOSYSTEM: ≥ 2.3.0, < 2.8.2

    Update to 2.8.2

  • 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
    Affected ranges
    • ECOSYSTEM: < 1.3.1-1ubuntu2+esm1

    Update to 1.3.1-1ubuntu2+esm1

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

    Versions
    • 1.5.7-2build1
    • 1.6.6-1build1
    • 1.6.7-1
    Affected ranges
    • ECOSYSTEM: < 1.6.7-1ubuntu0.1~esm1

    Update to 1.6.7-1ubuntu0.1~esm1

  • 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
    Affected ranges
    • ECOSYSTEM: < 2.4.2-2ubuntu0.1~esm1

    Update to 2.4.2-2ubuntu0.1~esm1

  • php-league-commonmark Ubuntu:25.10

    Versions
    • 2.6.1-2
    • 2.6.2-1
    • 2.7.0-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • php-league-commonmark Ubuntu:26.10

    Versions
    • 2.8.0-1
    • 2.8.2-2
    • 2.8.3-1
    • 2.10.0-1
    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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