{"id":"DEBIAN-CVE-2026-33721","details":"MapServer is a system for developing web-based GIS applications. Starting in version 4.2 and prior to version 8.6.1, a heap-buffer-overflow write in MapServer’s SLD (Styled Layer Descriptor) parser lets a remote, unauthenticated attacker crash the MapServer process by sending a crafted SLD with more than 100 Threshold elements inside a ColorMap/Categorize structure (commonly reachable via WMS GetMap with SLD_BODY). Version 8.6.1 patches the issue.","modified":"2026-09-14T17:03:08.492956897Z","published":"2026-03-27T01:16:19.670Z","upstream":["CVE-2026-33721"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-33721"}],"affected":[{"package":{"name":"mapserver","ecosystem":"Debian:12","purl":"pkg:deb/debian/mapserver?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"8.0.0-3+deb12u1"}]}],"versions":["8.0.0-3"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-33721.json"}},{"package":{"name":"mapserver","ecosystem":"Debian:13","purl":"pkg:deb/debian/mapserver?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"8.4.0-4+deb13u2"}]}],"versions":["8.4.0-4","8.4.0-4+deb13u1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-33721.json"}},{"package":{"name":"mapserver","ecosystem":"Debian:14","purl":"pkg:deb/debian/mapserver?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"8.6.1-1"}]}],"versions":["8.4.0-4","8.4.1-1","8.4.1-1~bpo13+1","8.4.1-2","8.6.0-1","8.6.0-1~bpo13+1","8.6.0~beta1-1~exp1","8.6.0~beta2-1~exp1","8.6.0~rc1-1~exp1","8.6.1-1~bpo13+1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-33721.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}