This advisory covers eight security vulnerabilities in the Linux kernel packages for Red Hat Enterprise Linux 9.4. The issues include: CVE-2026-23455 (netfilter nf_conntrack_h323 zero-length check), CVE-2026-31669 (mptcp slab-use-after-free), CVE-2026-43128 (RDMA/umem double dma_buf_unpin), CVE-2026-43329 (netfilter flowtable action count check), CVE-2026-46331 (net/sched act_pedit skb range extension), CVE-2026-43501 (ipv6 rpl mac_len headroom reservation), CVE-2026-45852 (RDMA/rxe double free), and CVE-2026-46173 (kernel exit preemption prevention). These vulnerabilities affect critical kernel subsystems and could lead to memory corruption or denial of service. The advisory also includes bug fixes and enhancements related to recursive locking detection. The update is rated as Important by Red Hat Product Security and requires a system reboot.

The vulnerabilities impact the Linux kernel in Red Hat Enterprise Linux 9.4, potentially allowing memory corruption issues such as use-after-free and double free, which could lead to system instability or denial of service. Improper input validation could also cause unexpected behavior in network packet processing. The overall security impact is rated as Important (high severity) by Red Hat. There are no known exploits in the wild at the time of this advisory.

Red Hat has released an updated kernel package for Red Hat Enterprise Linux 9.4 that addresses these vulnerabilities. Users should apply the update promptly and reboot their systems to ensure the fixes take effect. For detailed update instructions, refer to Red Hat's official advisory at https://access.redhat.com/articles/11258. No additional mitigations are specified beyond applying the official update and rebooting.