{"cve":"CVE-2026-33721","nvd":{"published":"2026-03-27T01:16:19.670","modified":"2026-06-17T10:37:59.190","status":"Modified","description":"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.","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-787"],"references":["https://github.com/MapServer/MapServer/releases/tag/rel-8-6-1","https://github.com/MapServer/MapServer/security/advisories/GHSA-cv4m-mr84-fgjp","https://lists.debian.org/debian-lts-announce/2026/04/msg00017.html"],"products":["osgeo:mapserver"],"source":"nvd","synced_at":"2026-10-19T22:28:18.033120106+00:00"},"epss":{"cve":"CVE-2026-33721","score":0.0122,"percentile":0.68676,"date":"2026-10-31"},"kev":null,"osv":[],"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."]}