CVE-2026-33721

MEDIUM

5.3

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.

CVE Details

CVSS v3.1 Score5.3

SeverityMEDIUM

CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Attack VectorNETWORK

ComplexityLOW

Privileges RequiredNONE

User InteractionNONE

Published3/27/2026

Last Modified4/1/2026

Sourcenvd

Honeypot Sightings0

Affected Products

osgeo:mapserver

Weaknesses (CWE)

CWE-787

References

https://github.com/MapServer/MapServer/releases/tag/rel-8-6-1(security-advisories@github.com)

https://github.com/MapServer/MapServer/security/advisories/GHSA-cv4m-mr84-fgjp(security-advisories@github.com)

IOC Correlations

No correlations recorded

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