RHSA-2026:2821 - Security Advisory

Topic

An update for kernel-rt is now available for Red Hat Enterprise Linux 8.

Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements.

Security Fix(es):

• kernel: smc: Use __sk_dst_get() and dst_dev_rcu() in smc_clc_prfx_match() (CVE-2025-40168)
• kernel: Linux kernel Bluetooth: Denial of Service due to use-after-free in connection handling (CVE-2023-53762)
• kernel: Linux kernel: Out-of-bounds write in fbdev can lead to privilege escalation, information disclosure, or denial of service. (CVE-2025-40304)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

The system must be rebooted for this update to take effect.

Affected Products

• Red Hat Enterprise Linux for Real Time 8 x86_64
• Red Hat Enterprise Linux for Real Time for NFV 8 x86_64

Fixes

• BZ - 2414482 - CVE-2025-40168 kernel: smc: Use __sk_dst_get() and dst_dev_rcu() in smc_clc_prfx_match()
• BZ - 2419838 - CVE-2023-53762 kernel: Linux kernel Bluetooth: Denial of Service due to use-after-free in connection handling
• BZ - 2419870 - CVE-2025-40304 kernel: Linux kernel: Out-of-bounds write in fbdev can lead to privilege escalation, information disclosure, or denial of service.

CVEs

• CVE-2023-53762
• CVE-2025-40168
• CVE-2025-40304

References

• https://access.redhat.com/security/updates/classification/#moderate