What is CVE-2026-42030?

CVE-2026-42030 is a medium-severity vulnerability in Mapserver, classified under Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS). CVSS score: 6.1/10. Published 2026-05-08.

How severe is CVE-2026-42030?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Mapserver

CVE-2026-42030

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…

EPSS: 0.000 (4.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

Affected products

Mapserver — versions >= 6.0, < 8.6.2
Osgeo Mapserver

Weakness classification (CWE)

CWE-80 — Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)

References

security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
security-advisories@github.com (Product, x_refsource_MISC, Release Notes)

Frequently asked questions

What is CVE-2026-42030?: CVE-2026-42030 is a medium-severity vulnerability in Mapserver, classified under Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS). CVSS score: 6.1/10. Published 2026-05-08.
How severe is CVE-2026-42030?: Medium severity. CVSS v3 base score is 6.1 out of 10.