LinuxCNC up to 2.9.8 dlopen path traversal

Summaryinfo

A vulnerability classified as critical has been found in LinuxCNC up to 2.9.8. The affected element is the function dlopen. The manipulation leads to path traversal. This vulnerability is referenced as CVE-2026-58302. The attack can only be performed from a local environment. No exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in LinuxCNC up to 2.9.8 and classified as critical. This issue affects the function dlopen. The manipulation with an unknown input leads to a path traversal vulnerability. Using CWE to declare the problem leads to CWE-22. The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

rtapi_app in linuxcnc-uspace in LinuxCNC before 2.9.9 allows privilege escalation. It is installed SUID root and loads shared library modules via dlopen() by using a user-supplied module name. Insufficient validation of the module name allows path traversal, enabling an unprivileged local user to load an arbitrary shared library. Because the process retains elevated privileges during module loading, this results in local privilege escalation to root.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-58302 since 06/30/2026. The exploitation is known to be easy. An attack has to be approached locally. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1006 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 323880 (Linux Distros Unpatched Vulnerability : CVE-2026-58302), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.9.9 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 00d534c87464a3ed446656998aa02b8abc74b391 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (323880). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Name

• LinuxCNC

Version

• 2.9.0
• 2.9.1
• 2.9.2
• 2.9.3
• 2.9.4
• 2.9.5
• 2.9.6
• 2.9.7
• 2.9.8

License

• open-source

Website

• Product: https://github.com/LinuxCNC/linuxcnc/

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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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