CVEvulnerability
CVE-2026-33721
7.5 HIGH
Official page ↗
- Status
- Modified
- Published
- 2026-03-27
- Last modified
- 2026-06-17
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 5.3 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- CVSS 3.1 ([email protected])
- 7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-787
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.
Affected configurations
• osgeo mapserver (>= 4.2.0 < 8.6.1)
Related
Weakness · CWE (1)
- CWE-787 Out-of-bounds Write weakness
References
- https://github.com/MapServer/MapServer/releases/tag/rel-8-6-1 Product, Release Notes
- https://github.com/MapServer/MapServer/security/advisories/GHSA-cv4m-mr84-fgjp Exploit, Mitigation, Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2026/04/msg00017.html lists.debian.org