Linux Kernel up to 7.0.3 SELinux Security Mode mmap access control

Summaryinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 7.0.3. Impacted is the function mmap of the component SELinux Security Mode. This manipulation causes access control. This vulnerability appears as CVE-2026-46054. There is no available exploit. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel up to 7.0.3. Affected by this vulnerability is the function mmap of the component SELinux Security Mode. The manipulation with an unknown input leads to a access control vulnerability. The CWE definition for the vulnerability is CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: selinux: fix overlayfs mmap() and mprotect() access checks The existing SELinux security model for overlayfs is to allow access if the current task is able to access the top level file (the "user" file) and the mounter's credentials are sufficient to access the lower level file (the "backing" file). Unfortunately, the current code does not properly enforce these access controls for both mmap() and mprotect() operations on overlayfs filesystems. This patch makes use of the newly created security_mmap_backing_file() LSM hook to provide the missing backing file enforcement for mmap() operations, and leverages the backing file API and new LSM blob to provide the necessary information to properly enforce the mprotect() access controls.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2026-46054 since 05/13/2026. The exploitation appears to be easy. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 06/17/2026). The attack technique deployed by this issue is T1068 according to MITRE ATT&CK.

The vulnerability scanner Nessus provides a plugin with the ID 320691 (AlmaLinux 10 : kernel (ALSA-2026:25191)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 7.0.4 or 7.1-rc1 eliminates this vulnerability. Applying the patch cd0e707a927a70cdfd8bc5a512a9719a87f5ed51/82544d36b1729153c8aeb179e84750f0c085d3b1 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (320691). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 7.0.0
• 7.0.1
• 7.0.2
• 7.0.3

License

• open-source

Website

• Vendor: https://www.kernel.org/

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