{"cve":"CVE-2026-59926","nvd":{"published":"2026-07-08T17:17:28.323","modified":"2026-10-25T17:10:00.197","status":"Analyzed","description":"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 escaping, allowing attribute injection and cross-site scripting even when HTMLRenderer escape mode is enabled. This issue is fixed in version 3.2.1.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N","score":5.3},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","score":6.1},"cwes":["CWE-79"],"references":["https://github.com/lepture/mistune/commit/a3cb6e5655308797e8be021d6c7b5bab13cbace2","https://github.com/lepture/mistune/releases/tag/v3.2.1","https://github.com/lepture/mistune/security/advisories/GHSA-g97x-gvcm-x72h"],"products":["mistune_project:mistune"],"source":"nvd","synced_at":"2026-10-25T17:50:06.907763985+00:00"},"epss":{"cve":"CVE-2026-59926","score":0.00327,"percentile":0.25545,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-g97x-gvcm-x72h","url":"https://osv.dev/vulnerability/GHSA-g97x-gvcm-x72h","summary":"Mistune: XSS via unescaped class option in Admonition directive","modified":"2026-07-20T21:46:40.083797845Z","packages":[{"ecosystem":"PyPI","name":"mistune","purl":"pkg:pypi/mistune","ranges":["<3.3.0"],"fixed":["3.3.0"]}]},{"id":"PYSEC-2026-2214","url":"https://osv.dev/vulnerability/PYSEC-2026-2214","summary":"","modified":"2026-07-13T07:15:18.821076445Z","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."]}