Medium 6.1Published May 8, 2026

CVE-2026-42030MapServer: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS) in OpenLayers viewer

Updated under an hour ago (Oct 28, 2026, 5:20 PM ET)

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It affects MapServer and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for MapServer

Exploited in the last 30 days

MapServer is a system for developing web-based GIS applications. From version 6.0 to before version 8.6.2, a reflected XSS vulnerability in MapServer's WMS server allows an unauthenticated attacker to inject arbitrary HTML/JavaScript into the browser of any user who opens a crafted WMS URL. The vulnerability is triggered via FORMAT=application/openlayers combined with an unsanitized SRS parameter in WMS 1.3.0 requests. This issue has been patched in version 8.6.2.

CVSS: 6.1 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Weakness (CWE): CWE-80
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: May 8, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

MapServer MapServer mapserver:mapserver (from the name)	from 6.0, < 8.6.2	CNA record
osgeo mapserver osgeo:mapserver	from 6.0.0 before 8.6.2	NVD

References

References

https://github.com/MapServer/MapServer/security/advisories/GHSA-4g9f-ph64-hg2x	x-refsource-confirm, exploit, vendor-advisory
https://github.com/MapServer/MapServer/releases/tag/rel-8-6-2	x-refsource-misc, product, release-notes

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.