{"cve":"CVE-2026-59928","nvd":{"published":"2026-07-08T17:17:28.600","modified":"2026-10-25T17:10:00.197","status":"Analyzed","description":"Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, a Markdown document containing many repeated or distinct reference-link definitions causes quadratic work in src/mistune/block_parser.py and the ref_links environment dictionary handling, allowing denial of service through CPU exhaustion. This issue is fixed in version 3.3.0.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-407","CWE-1333"],"references":["https://github.com/lepture/mistune/commit/2b04d7ba341c16ac78fe82d3076bdd5c3de87c69","https://github.com/lepture/mistune/releases/tag/v3.3.0","https://github.com/lepture/mistune/security/advisories/GHSA-ffq3-xpv3-j92q","https://github.com/lepture/mistune/security/advisories/GHSA-ffq3-xpv3-j92q"],"products":["mistune_project:mistune"],"source":"nvd","synced_at":"2026-10-25T17:50:06.907763985+00:00"},"epss":{"cve":"CVE-2026-59928","score":0.00651,"percentile":0.50902,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-ffq3-xpv3-j92q","url":"https://osv.dev/vulnerability/GHSA-ffq3-xpv3-j92q","summary":"Mistune block_parser: quadratic-time parsing on long lists of repeated reference-link definitions","modified":"2026-07-20T21:30:38.320453360Z","packages":[{"ecosystem":"PyPI","name":"mistune","purl":"pkg:pypi/mistune","ranges":["<3.3.0"],"fixed":["3.3.0"]}]},{"id":"PYSEC-2026-2216","url":"https://osv.dev/vulnerability/PYSEC-2026-2216","summary":"","modified":"2026-07-13T07:15:18.812243616Z","packages":[{"ecosystem":"PyPI","name":"mistune","purl":"pkg:pypi/mistune","ranges":["<3.3.0"],"fixed":["3.3.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}