CVE-2026-33721

5.3 MEDIUM
Published: March 27, 2026 Modified: April 17, 2026
View on NVD

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 MapServerโ€™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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/MapServer/MapServer/releases/tag/rel-8-6-1
Source: security-advisories@github.com
Product Release Notes
https://github.com/MapServer/MapServer/security/advisories/GHSA-cv4m-mr84-fgjp
Source: security-advisories@github.com
Exploit Mitigation Vendor Advisory

3 reference(s) from NVD

Quick Stats

CVSS v3 Score
5.3 / 10.0
EPSS (Exploit Probability)
0.2%
41th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

osgeo