{"id":"CVE-2026-59922","aliases":["PYSEC-2026-2210","GHSA-c8j7-8cv4-2xmq"],"title":"Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, a run of closed tilde, equals-sign, or caret marker pairs…","summary":"Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, a run of closed tilde, equals-sign, or caret marker pairs around a character causes quadratic work in src/mistune/plugins/formatting.py when the strikethroug…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","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-2026-2210","references":[{"url":"https://github.com/lepture/mistune/releases/tag/v3.3.0"},{"url":"https://github.com/lepture/mistune/commit/96d0f57f8fe9eeb06bb4cff521962a27d7c402e7"},{"url":"https://github.com/lepture/mistune/security/advisories/GHSA-c8j7-8cv4-2xmq"}],"tags":["osv","pip"],"epss":0.00644,"epssPercentile":0.49449,"ingestedAt":"2026-07-13T18:58:08.108Z","slug":"CVE-2026-59922","body":"## Overview\n\nMistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, a run of closed tilde, equals-sign, or caret marker pairs around a character causes quadratic work in src/mistune/plugins/formatting.py when the strikethrough, mark, or insert plugin scans for matching markers from each possible start position, allowing denial of service through CPU exhaustion. 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":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}