CVE-2026-59930Medium· 4.3▾ SunlitMistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, the toc plugin and TableOfContents directive generate heading IDs as predictable toc_N values without slugifying the heading text, allowing attacker-controll…
▾ Sunlit zone — Low / medium · no exploitation signal
impact 23.7 · likelihood 0 · exploitation 0
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Exploit-prediction probability, daily snapshots since Jul 13.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via OSV
Last analysed / modified upstream
0.1%
0.1% → 0.2%
Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, the toc plugin and TableOfContents directive generate heading IDs as predictable toc_N values without slugifying the heading text, allowing attacker-controlled id="toc_N" content to collide with generated anchors and redirect same-page navigation, CSS selectors, or JavaScript handlers. This issue is fixed in version 3.3.0.
mistune < 3.3.0Upgrade to a patched release:
mistune 3.3.0Connected by shared product, vendor, weakness, or advisory.
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