VDB
CVE-2026-33721
CVE-2026-33721
PUBLISHED
CVSS 5.300000190734863 MEDIUM
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.
EPSS 1.22% · 68.5th percentile
Risk Scores
CVSS 3.1
5.300000190734863
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS Score
1.22%
68.5th percentile
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| osgeo | mapserver | 4.2.0 |
| MapServer | MapServer | >= 4.2, < 8.6.1 |
Timeline
- Mar 27, 2026 Coalition ESS Score
- Mar 27, 2026 CVE Published
- Apr 17, 2026 CVE Updated
- May 18, 2026 EPSS Score
- May 19, 2026 EPSS Score
- May 21, 2026 EPSS Score
- May 22, 2026 EPSS Score
- May 24, 2026 EPSS Score
- May 25, 2026 EPSS Score
- May 27, 2026 EPSS Score
- May 28, 2026 EPSS Score
- May 30, 2026 EPSS Score