{"id":"CVE-2026-59926","aliases":["PYSEC-2026-2214","GHSA-g97x-gvcm-x72h"],"title":"Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.2.1, render_admonition() in src/mistune/directives/admonition.…","summary":"Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.2.1, render_admonition() in src/mistune/directives/admonition.py concatenates the Admonition directive :class: option into the HTML class attribute without escapi…","severity":"medium","cvss":6.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","vendor":"mistune","product":"mistune","ecosystem":"pip","affected":["mistune < 3.3.0"],"patched":["mistune 3.3.0"],"published":"2026-07-08","updated":"2026-07-13","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/PYSEC-2026-2214","references":[{"url":"https://github.com/lepture/mistune/releases/tag/v3.2.1"},{"url":"https://github.com/lepture/mistune/security/advisories/GHSA-g97x-gvcm-x72h"},{"url":"https://github.com/lepture/mistune/commit/a3cb6e5655308797e8be021d6c7b5bab13cbace2"}],"tags":["osv","pip"],"epss":0.00327,"epssPercentile":0.23127,"ingestedAt":"2026-07-13T18:58:08.182Z","slug":"CVE-2026-59926","body":"## Overview\n\nMistune is a Python Markdown parser with renderers and plugins. Prior to 3.2.1, render_admonition() in src/mistune/directives/admonition.py concatenates the Admonition directive :class: option into the HTML class attribute without escaping, allowing attribute injection and cross-site scripting even when HTMLRenderer escape mode is enabled. This issue is fixed in version 3.2.1.\n\n## Affected packages\n\n- `mistune < 3.3.0`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `mistune 3.3.0`","depth":"sunlit","depthScore":34,"depthScoreParts":{"impact":33.6,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}