CVE-2026-59930

medium

Description

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.

References

https://github.com/lepture/mistune/security/advisories/GHSA-2hm2-hc3v-44h9

https://github.com/lepture/mistune/releases/tag/v3.3.0

https://github.com/lepture/mistune/commit/c4093c4742ed0d10d9332fb8edb455869b7b581b

Details

Source: Mitre, NVD

Published: 2026-07-08

Updated: 2026-07-08

Risk Information

CVSS v2

Base Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 4.3

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N

Severity: Medium