{"id":"CVE-2026-59929","aliases":["PYSEC-2026-2217","GHSA-qfrw-5rxm-mhh2"],"title":"Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, the safe_url filter in src/mistune/renderers/html.py bloc…","summary":"Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, the safe_url filter in src/mistune/renderers/html.py blocks only javascript:, vbscript:, file:, and data: schemes, allowing legacy or chained schemes such as…","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-2026-2217","references":[{"url":"https://github.com/lepture/mistune/releases/tag/v3.3.0"},{"url":"https://github.com/lepture/mistune/commit/c7101fcbb6e8790e8e39157c5ca2238fc6dd6cbc"},{"url":"https://github.com/lepture/mistune/security/advisories/GHSA-qfrw-5rxm-mhh2"}],"tags":["osv","pip"],"epss":0.00341,"epssPercentile":0.27762,"ingestedAt":"2026-07-13T18:58:08.238Z","slug":"CVE-2026-59929","body":"## Overview\n\nMistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, the safe_url filter in src/mistune/renderers/html.py blocks only javascript:, vbscript:, file:, and data: schemes, allowing legacy or chained schemes such as feed:, view-source:, jar:, livescript:, mocha:, ms-its:, mk:, and res: to reach rendered href and src attributes and potentially execute script in affected user agents. This issue is fixed in version 3.3.0.\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":[]}