Medium severity · published May 8, 2026
CVE-2026-42030
MapServer: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS) in OpenLayers viewer
6.1
CVSS
0.2%
EPSS
No
On KEV
Description
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 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 16% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MA
MapServer · MapServer
>= 6.0, < 8.6.2 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-42030
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-42030
Product
https://github.com/MapServer/MapServer/releases/tag/rel-8-6-2
Exploit
https://github.com/MapServer/MapServer/security/advisories/GHSA-4g9f-ph64-hg2x
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