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CVE-2026-59925

CVE-2026-59925 · inline_parser: quadratic-time parsing on long runs of `**x**` and `***x***` emphasis pairs

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

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, long sequences of well-formed double-asterisk or triple-asterisk emphasis pairs around a character cause quadratic work in src/mistune/inline_parser.py because the parser scans forward for matching close markers from every potential opening run, allowing denial of service in default Mistune parsing. This issue is fixed in version 3.3.0.

CVSS 7.5 · High · EPSS 0.6% · Fix available

Published
Updated

Stack: system · python

Affected products and versions

  • mistune

    Versions
    • < 3.3.0: Affected

    No fix published

  • mistune Debian:13

    Versions
    • 3.1.3-1
    • 3.1.4-1
    • 3.3.4-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • mistune Debian:14

    Versions
    • 3.1.3-1
    • 3.1.4-1
    • 3.3.4-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • mistune PyPI

    Versions
    • 0.1.0
    • 0.2.0
    • 0.3.0
    • 0.3.1
    • 0.4
    • 0.4.1
    • 0.5
    • 0.5.1
    • 0.6
    • 0.7
    • 0.7.1
    • 0.7.2
    • 0.7.3
    • 0.7.4
    • 0.8
    • 0.8.1
    • 0.8.2
    • 0.8.3
    • 0.8.4
    • 2.0.0
    • 2.0.0a1
    • 2.0.0a2
    • 2.0.0a3
    • 2.0.0a4
    • 2.0.0a5
    • 2.0.0a6
    • 2.0.0rc1
    • 2.0.1
    • 2.0.2
    • 2.0.3
    • 2.0.4
    • 2.0.5
    • 2.1.0
    • 3.0.0
    • 3.0.0a1
    • 3.0.0a2
    • 3.0.0a3
    • 3.0.0rc1
    • 3.0.0rc2
    • 3.0.0rc3
    • 3.0.0rc4
    • 3.0.0rc5
    • 3.0.1
    • 3.0.2
    • 3.1.0
    • 3.1.1
    • 3.1.2
    • 3.1.3
    • 3.1.4
    • 3.2.0
    • 3.2.1
    Affected ranges
    • ECOSYSTEM: < 3.3.0

    Update to 3.3.0

  • mistune Ubuntu:16.04:LTS

    Versions
    • 0.6-2
    • 0.7.1-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • mistune Ubuntu:18.04:LTS

    Versions
    • 0.7.4-1
    • 0.8-1
    • 0.8.1-1
    • 0.8.3-2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • mistune Ubuntu:20.04:LTS

    Versions
    • 0.8.4-1
    • 0.8.4-2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • mistune Ubuntu:22.04:LTS

    Versions
    • 0.8.4-4
    • 0.8.4-5
    • 2.0.0-1+really0.8.4-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • mistune Ubuntu:24.04:LTS

    Versions
    • 2.0.4-2
    • 3.0.2-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • mistune Ubuntu:25.10

    Versions
    • 3.0.2-2
    • 3.1.3-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • mistune Ubuntu:26.10

    Versions
    • 3.1.4-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • mistune Ubuntu:26.04:LTS

    Versions
    • 3.1.3-1
    • 3.1.4-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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