{"id":"DEBIAN-CVE-2026-44898","details":"Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.2.1, render_toc_ul() builds a \u003cul\u003e table-of-contents tree from a list of (level, id, text) tuples. Both the id value (used as href=\"#\u003cid\u003e\") and the text value (used as the visible link label) are inserted into \u003ca\u003e tags via a plain Python format string — with no HTML escaping applied to either value. When heading IDs are derived from user-supplied heading text (the standard use-case for readable slug anchors), an attacker can craft a heading whose text breaks out of the href=\"#...\" attribute context, injecting arbitrary HTML tags including \u003cscript\u003e blocks directly into the rendered TOC. This vulnerability is fixed in 3.2.1.","modified":"2026-09-01T16:06:45.026127690Z","published":"2026-05-26T21:16:39.810Z","upstream":["CVE-2026-44898"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-44898"}],"affected":[{"package":{"name":"mistune","ecosystem":"Debian:12","purl":"pkg:deb/debian/mistune?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.0.4-1","2.0.4-2","3.0.2-1","3.0.2-2","3.1.3-1","3.1.4-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-44898.json"}},{"package":{"name":"mistune","ecosystem":"Debian:13","purl":"pkg:deb/debian/mistune?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.1.3-1","3.1.4-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-44898.json"}},{"package":{"name":"mistune","ecosystem":"Debian:14","purl":"pkg:deb/debian/mistune?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.1.3-1","3.1.4-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-44898.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"}]}