CVE-2026-42030

Name	CVE-2026-42030
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.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
mapserver (PTS)	bullseye	7.6.2-1	vulnerable
	bullseye (security)	7.6.2-1+deb11u2	vulnerable
	bookworm	8.0.0-3+deb12u1	vulnerable
	trixie	8.4.0-4+deb13u2	vulnerable
	forky, sid	8.6.3-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
mapserver	source	(unstable)	8.6.2-1

[bullseye] - mapserver <postponed> (Minor issue, reflected XSS)
https://github.com/MapServer/MapServer/security/advisories/GHSA-4g9f-ph64-hg2x