This advisory addresses five use-after-free vulnerabilities in the Red Hat kernel-rt packages: CVE-2025-38129 in page_pool_recycle_in_ring, CVE-2025-38248 in bridge multicast initialization, CVE-2025-40064 in __pnet_find_base_ndev(), CVE-2025-68800 in mlxsw spectrum_mr multicast route stats update, and CVE-2026-23074 in the teql queueing discipline which can lead to privilege escalation. These vulnerabilities affect the Real Time Linux Kernel used for systems requiring high determinism. The advisory provides updated kernel-rt packages for Red Hat Enterprise Linux 8 Real Time variants. The update must be applied and the system rebooted to mitigate the issues. The vendor rates the security impact as important but does not provide CVSS scores in this advisory.

Successful exploitation of these use-after-free vulnerabilities could lead to privilege escalation and potential system compromise on affected Red Hat Enterprise Linux Real Time systems. The vulnerabilities affect kernel components responsible for memory management, network bridge multicast, SMC networking, multicast routing statistics, and queueing disciplines, which are critical for system stability and security.

Red Hat has released updated kernel-rt packages that fix these vulnerabilities. Users should apply the security update RHSA-2026:3110 for Red Hat Enterprise Linux 8 Real Time and reboot the system for the update to take effect. Refer to https://access.redhat.com/articles/11258 for detailed update instructions. No alternative mitigations are indicated; applying the official update and rebooting is required.