This advisory covers four Linux kernel vulnerabilities fixed in Red Hat Enterprise Linux 9 and its variants. CVE-2026-23060 addresses a denial of service in the authencesn component caused by too-short Additional Authenticated Data (AAD). CVE-2026-31431 reverts the algif_aead cryptographic operation to out-of-place processing to fix a flaw. CVE-2026-31677 limits RX scatter-gather extraction by the receive buffer budget in the af_alg crypto subsystem. CVE-2026-43284, dubbed "Dirty Frag," is a new universal local privilege escalation vulnerability in the ESP XFRM variant of the Linux kernel. Red Hat has rated the update as important and requires rebooting systems after applying the update.

Successful exploitation of these vulnerabilities could lead to denial of service conditions or local privilege escalation on affected systems running Red Hat Enterprise Linux 9. The denial of service vulnerability (CVE-2026-23060) may disrupt kernel operations. The local privilege escalation vulnerability (CVE-2026-43284) could allow an attacker with local access to gain elevated privileges. The cryptographic fixes address potential weaknesses in kernel crypto operations that could impact system security.

Red Hat has released an official security update for the Linux kernel packages in Red Hat Enterprise Linux 9 and related variants. Applying this update and rebooting the system is required to remediate these vulnerabilities. For detailed update instructions, refer to the Red Hat advisory at https://access.redhat.com/articles/11258. No additional mitigation steps are indicated beyond applying the official update and rebooting.