Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS) in MapServer - CVE-2026-42030
Published: April 20, 2026
Vulnerability identifier: #VU126492
CSH Severity: Medium
CVSS v4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-42030
CWE-ID: CWE-80
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary JavaScript in the browser of a user who opens a crafted URL.
The vulnerability exists due to improper neutralization of script-related html tags in the OpenLayers viewer output of the WMS server when processing WMS 1.3.0 requests with FORMAT=application/openlayers and an unsanitized SRS parameter. A remote attacker can send a specially crafted WMS URL to execute arbitrary JavaScript in the browser of a user who opens a crafted URL.
User interaction is required to open the crafted URL.
Affected software
MapServer
Fedora
mapserver
Fedora
mapserver
How to mitigate CVE-2026-42030
Install security update from vendor's website.
MapServer - update to 8.6.2
mapserver - update to 8.6.3-1.fc43
mapserver - update to 8.6.3-1.fc43