CVE-2026-33721
MapServer has heap buffer overflow in SLD `Categorize` Threshold parsing
- State
- Published
- Severity
- 5.3 Medium
- Published
- Mar 27, 2026
- Updated
- Apr 17, 2026
- Reserved
- Mar 23, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 5.3 Medium | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L | GitHub_M |
Weaknesses
- CWE-787 Out-of-bounds Write
Affected Products
| Product | Versions |
|---|---|
MapServerMapServer |
|
References
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