MapServer up to 8.6.1 WMS SRS cross site scripting

Summaryinfo

A vulnerability marked as problematic has been reported in MapServer up to 8.6.1. Affected is an unknown function of the component WMS Handler. This manipulation of the argument SRS causes cross site scripting. This vulnerability is tracked as CVE-2026-42030. The attack is possible to be carried out remotely. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability has been found in MapServer up to 8.6.1 and classified as problematic. Affected by this vulnerability is an unknown code of the component WMS Handler. The manipulation of the argument SRS with an unknown input leads to a cross site scripting vulnerability. The CWE definition for the vulnerability is CWE-80. The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes special characters such as "<", ">", and "&" that could be interpreted as web-scripting elements when they are sent to a downstream component that processes web pages. As an impact it is known to affect integrity. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-42030 since 04/23/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1059.007 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 313441 (Linux Distros Unpatched Vulnerability : CVE-2026-42030), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 8.6.2 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (313441). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Name

• MapServer

Version

• 8.6.0
• 8.6.1

Website

• Product: https://github.com/MapServer/MapServer/

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If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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