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.
Fix
Patch, vendor advisory and mitigation references on NVD 1
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 4.3 · mistune_projectNVD modified 2026-10-25 17:10
Affected (CPE criteria) 1
cpe:2.3:a:mistune_project:mistune:*:*:*:*:*:*:*:*
References 4
- https://github.com/lepture/mistune/commit/c4093c4742ed0d10d9332fb8edb455869b7b581b Patch
- https://github.com/lepture/mistune/releases/tag/v3.3.0 Release Notes
- https://github.com/lepture/mistune/security/advisories/GHSA-2hm2-hc3v-44h9 Exploit, Third Party Advisory
- https://github.com/lepture/mistune/security/advisories/GHSA-2hm2-hc3v-44h9 Exploit, Third Party Advisory