{"id":"CVE-2026-59925","aliases":["GHSA-4j32-57v6-6g45","PYSEC-2026-2213"],"url":"https://o3.security/vulnerability/CVE-2026-59925","summary":"inline_parser: quadratic-time parsing on long runs of `**x**` and `***x***` emphasis pairs","details":"Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, long sequences of well-formed double-asterisk or triple-asterisk emphasis pairs around a character cause quadratic work in src/mistune/inline_parser.py because the parser scans forward for matching close markers from every potential opening run, allowing denial of service in default Mistune parsing. This issue is fixed in version 3.3.0.","published":"2026-07-08T16:18:43.786Z","modified":"2026-08-12T03:51:31.731764114Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"mistune","fixedVersion":"3.3.0"}],"fix":{"url":"https://github.com/lepture/mistune/commit/5de41fb8e527004dbc363e047a3c380c9288c74f","label":"lepture/mistune@5de41fb"},"references":[{"type":"WEB","url":"https://github.com/lepture/mistune/releases/tag/v3.3.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59925.json"},{"type":"ADVISORY","url":"https://github.com/lepture/mistune/security/advisories/GHSA-4j32-57v6-6g45"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59925"},{"type":"FIX","url":"https://github.com/lepture/mistune/commit/5de41fb8e527004dbc363e047a3c380c9288c74f"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:31.731764114Z"}}