MapServer up to 8.6.2 array index

Summaryinfo

A vulnerability identified as problematic has been detected in MapServer up to 8.6.2. The affected element is an unknown function. The manipulation leads to array index. This vulnerability is referenced as CVE-2026-45104. Remote exploitation of the attack is possible. No exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in MapServer up to 8.6.2. It has been rated as problematic. This issue affects some unknown functionality. The manipulation with an unknown input leads to a array index vulnerability. Using CWE to declare the problem leads to CWE-129. The product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array. Impacted is availability. The summary by CVE is:

MapServer is a system for developing web-based GIS applications. From 6.4.0 to before 8.6.3, msSLDParseUserStyle always calls _SLDApplyRuleValues(psRule, psLayer, 1); for any carrying — it assumes msSLDParseRule added one class. When the rule has no symbolizer (a structurally valid SLD), msSLDParseRule adds zero, and _SLDApplyRuleValues ends up indexing _class[-1], resulting in a NULL pointer dereference. A 200-byte well-formed SLD via the WMS SLD_BODY= parameter is enough to trigger this, no auth required. This vulnerability is fixed in 8.6.3.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-45104 since 05/08/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. The technical details are unknown and an exploit is not publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 318158 (Linux Distros Unpatched Vulnerability : CVE-2026-45104), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 8.6.3 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (318158) and EUVD (EUVD-2026-32631). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Name

• MapServer

Version

• 8.6.0
• 8.6.1
• 8.6.2

Website

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

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Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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