🛡️ CVE-2026-33721
🟡 CVSS 5.3 — Medium ⚠️ Exploit Public CWE-787 NVD
5.3
CVSS Score
0 Low4 Medium7 High9 Critical10

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.

Details

Severity MEDIUM
CVSS Score 5.3
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CWE CWE-787
Public Exploit ⚠️ Yes
Source NVD
Published 2026-03-27
Updated 2026-06-02
Modified 2026-04-17
Fix URL N/A

Affected Packages

Software From version Fixed in
mapserver 4.2.0 8.6.1

Patch Gap Protection

Running software with known vulnerabilities?

BotEraser can help reduce exposure by blocking IPs associated with exploit activity — even before a patch is available.

Start Free →

No credit card required  ·  Results in minutes

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.