CVE-2026-33721
Detail
Modified After Enrichment
This CVE record has been updated after NVD enrichment efforts were completed. Enrichment data supplied by the NVD may require amendment due to these changes.
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.
Metrics
NVD enrichment efforts reference publicly available information to associate
vector strings. CVSS information contributed by other sources is also
displayed.
CVSS 4.0 Severity and Vector Strings:
NVD assessment
not yet provided.
CVSS 3.x Severity and Vector Strings:
Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS 2.0 Severity and Vector Strings:
Base
Score:
NVD assessment
not yet provided.
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Weakness Enumeration
| CWE-ID |
CWE Name |
Source |
|
CWE-787
|
Out-of-bounds Write |
GitHub, Inc.
|
Change History
5 change records found show changes
CVE Modified by CISA-ADP
6/17/2026 6:37:59 AM
| Action |
Type |
Old Value |
New Value |
| Added |
SSVC |
{"timestamp":"2026-03-30T11:51:50.279171Z","id":"CVE-2026-33721","options":[{"exploitation":"poc"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}
|
CVE Modified by GitHub, Inc.
6/17/2026 6:37:59 AM
| Action |
Type |
Old Value |
New Value |
| Added |
Affected |
[{"vendor":"MapServer","product":"MapServer","versions":[{"version":">= 4.2, < 8.6.1","status":"affected"}]}]
|
CVE Modified by CVE
4/17/2026 2:16:31 PM
| Action |
Type |
Old Value |
New Value |
| Added |
Reference |
https://lists.debian.org/debian-lts-announce/2026/04/msg00017.html
|
Initial Analysis by NIST
4/01/2026 11:58:41 AM
| Action |
Type |
Old Value |
New Value |
| Added |
CVSS V3.1 |
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
|
| Added |
CPE Configuration |
OR
*cpe:2.3:a:osgeo:mapserver:*:*:*:*:*:*:*:* versions from (including) 4.2.0 up to (excluding) 8.6.1
|
| Added |
Reference Type |
GitHub, Inc.: https://github.com/MapServer/MapServer/releases/tag/rel-8-6-1 Types: Product, Release Notes
|
| Added |
Reference Type |
GitHub, Inc.: https://github.com/MapServer/MapServer/security/advisories/GHSA-cv4m-mr84-fgjp Types: Exploit, Mitigation, Vendor Advisory
|
New CVE Received from GitHub, Inc.
3/26/2026 9:16:19 PM
| Action |
Type |
Old Value |
New Value |
| Added |
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.
|
| Added |
CVSS V3.1 |
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
|
| Added |
CWE |
CWE-787
|
| Added |
Reference |
https://github.com/MapServer/MapServer/releases/tag/rel-8-6-1
|
| Added |
Reference |
https://github.com/MapServer/MapServer/security/advisories/GHSA-cv4m-mr84-fgjp
|
Quick Info
CVE Dictionary Entry: CVE-2026-33721 NVD
Published Date: 03/26/2026 NVD
Last Modified: 06/17/2026
Source: GitHub, Inc.
|
