CVE-2026-68284

A flaw was found in the Linux kernel. A use-after-free vulnerability exists in the tcp_bpf_sendmsg() function within the BPF (Berkeley Packet Filter) and sockmap components. This flaw occurs when two threads attempt to send data on the same socket concurrently, leading to an incorrect memory deallocation. A local attacker could exploit this to cause a system crash, resulting in a denial of service.

The default Red Hat Enterprise Linux kernel prevents unprivileged users from being able to use eBPF by the kernel.unprivileged_bpf_disabled sysctl. This would require a privileged user with CAP_SYS_ADMIN or root to be able to abuse this flaw reducing its attack space.

For the Red Hat Enterprise Linux 9 to confirm the current state, inspect the sysctl with the command:

cat /proc/sys/kernel/unprivileged_bpf_disabled

The setting of 1 would mean that unprivileged users can not use eBPF, mitigating the flaw.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.