CVE-2026-44896

Mistune: XSS via unescaped figclass/figwidth in Figure directive

State
Published
Severity
5.3 Medium
Published
May 26, 2026
Updated
Jun 8, 2026
Reserved
May 7, 2026

Read the record on cve.org

Description

Mistune is a Python Markdown parser with renderers and plugins. In 3.2.0 and earlier, in src/mistune/directives/image.py, the render_figure() function concatenates figclass and figwidth options directly into HTML attributes without escaping. This allows attribute injection and XSS even when HTMLRenderer(escape=True) is used, because these values bypass the inline renderer. Version 3.2.1 contains a patch.

Scores

CVSSScoreVectorSource
4.05.3 MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:NGitHub_M

Weaknesses

  • CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Affected Products

ProductVersions
mistunelepture
  • < 3.2.1Affected

References

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