{"id":"CVE-2026-59923","summary":"Mistune: XSS via percent-encoded javascript URI bypass in safe_url()","details":"Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, HTMLRenderer.safe_url() does not block percent-encoded javascript URIs, allowing attacker-supplied Markdown links or images to bypass URL protections and execute script in rendered HTML. This issue is fixed in version 3.3.0.","aliases":["GHSA-8c25-4j27-2rv3","PYSEC-2026-2211"],"modified":"2026-07-15T10:14:47.604050761Z","published":"2026-07-08T16:14:39.266Z","related":["openSUSE-SU-2026:21339-1"],"database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-79"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59923.json"},"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-2026-59923.json"},{"type":"ADVISORY","url":"https://github.com/lepture/mistune/security/advisories/GHSA-8c25-4j27-2rv3"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59923"},{"type":"FIX","url":"https://github.com/lepture/mistune/commit/c7101fcbb6e8790e8e39157c5ca2238fc6dd6cbc"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/lepture/mistune","events":[{"introduced":"0"},{"fixed":"15c3b79325125272263d7d42492ec8f757447191"},{"fixed":"c7101fcbb6e8790e8e39157c5ca2238fc6dd6cbc"}],"database_specific":{"cpe":"cpe:2.3:a:mistune_project:mistune:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"0"},{"fixed":"3.3.0"}],"source":["CPE_RANGE","REFERENCES"]}}],"versions":["v3.2.1","v3.2.0","v3.1.4","v3.1.3","v3.1.2","v3.1.1","v3.1.0","v3.0.1","v3.0.0","v3.0.0rc5","v3.0.0rc4","v3.0.0rc3","v3.0.0rc2","v3.0.0rc1","v3.0.0a3","v3.0.0a2","v3.0.0a1","v2.0.2","v2.0.1","v2.0.0","v2.0.0rc1","v2.0.0a6","v2.0.0a5","v2.0.0a4","v2.0.0a3","v2.0.0a2","v2.0.0a1","v0.8.4","v0.8.3","v0.8.2","v0.8.1","v0.8","v0.7.4","v0.7.3","v0.7.2","v0.7.1","v0.7","v0.6","v0.5.1","v0.5","v0.4.1","v0.4","v0.3.1","v0.3.0","v0.2.0","v0.1.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-59923.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"}]}