CVE-2026-46054 is a security vulnerability in the Linux kernel's SELinux module affecting overlayfs mmap() and mprotect() access checks. This flaw could allow improper access control enforcement in these kernel operations. Red Hat has issued a security advisory (RHSA-2026:27811) providing updated kernel packages for Red Hat Enterprise Linux 8 across several architectures. The advisory rates the update as Important and recommends applying the update and rebooting the system to activate the fix. The vulnerability is tracked under CWE-280 (Improper Access Control). No known exploits in the wild have been reported.

The vulnerability affects the core Linux kernel in Red Hat Enterprise Linux 8, potentially allowing bypass of SELinux access checks on overlayfs mmap() and mprotect() operations. This could lead to unauthorized access or privilege escalation if exploited. Red Hat rates the security impact as Important (high severity). No active exploitation has been reported to date.

Red Hat has released an official kernel update that fixes this vulnerability. Users should apply the updated kernel packages as per Red Hat's advisory RHSA-2026:27811 and reboot their systems to ensure the fix takes effect. For detailed update instructions, refer to https://access.redhat.com/articles/11258. No additional mitigation steps are required beyond applying the official patch and rebooting.