CVE-2026-59930

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.

CVSS v3 4.3 MEDIUM

4.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
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

Configurations

Configuration 1 (hide)

cpe:2.3:a:mistune_project:mistune:*:*:*:*:*:*:*:*

History

25 Oct 2026, 17:10

Type	Values Removed	Values Added
Summary		(es) Mistune es un analizador de Markdown para Python con renderizadores y plugins. Antes de la versión 3.3.0, el plugin toc y la directiva TableOfContents generan IDs de encabezado como valores predecibles toc_N sin slugificar el texto del encabezado, lo que permite que el contenido id=’toc_N’ controlado por el atacante colisione con los anclajes generados y redirija la navegación en la misma página, los selectores CSS o los manejadores de JavaScript. Este problema se ha solucionado en la versión 3.3.0.

Information

Published : 2026-07-08 17:17

Updated : 2026-10-25 17:10

NVD link : CVE-2026-59930

Mitre link : CVE-2026-59930

CVE.ORG link : CVE-2026-59930

JSON object : View

Products Affected

mistune_project

mistune

CWE

CWE-345

Insufficient Verification of Data Authenticity

CWE-1284

Improper Validation of Specified Quantity in Input

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