CVE-2026-42030

Name: CVE-2026-42030
Creator: NVD / NIST
Published: 2026-05-08T17:16:31.307+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 0.25%

Last modified Jun 17, 2026

CVE-2026-42030 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. 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. EPSS estimates a 0.25% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

6.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS Probability

0.25%

15.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-80

Affected Software

Vendor	Product	Versions
Osgeo	Mapserver	>= 6.0.0, < 8.6.2

References

https://github.com/MapServer/MapServer/releases/tag/rel-8-6-2Product, Release Notes
https://github.com/MapServer/MapServer/security/advisories/GHSA-4g9f-ph64-hg2xExploit, Vendor Advisory
https://github.com/MapServer/MapServer/security/advisories/GHSA-4g9f-ph64-hg2xExploit, Vendor Advisory

Timeline

Published: May 8, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-42030?

How severe is CVE-2026-42030?

CVE-2026-42030 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.25% probability of exploitation in the next 30 days.

How do I fix CVE-2026-42030?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-42030?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST