RHSA-2026:0443 - 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 Important. 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: media: rc: fix races with imon_disconnect() (CVE-2025-39993)
• kernel: sctp: avoid NULL dereference when chunk data buffer is missing (CVE-2025-40240)
• kernel: libceph: fix potential use-after-free in have_mon_and_osd_map() (CVE-2025-68285)

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 - 2404121 - CVE-2025-39993 kernel: media: rc: fix races with imon_disconnect()
• BZ - 2418832 - CVE-2025-40240 kernel: sctp: avoid NULL dereference when chunk data buffer is missing
• BZ - 2422801 - CVE-2025-68285 kernel: libceph: fix potential use-after-free in have_mon_and_osd_map()

CVEs

• CVE-2025-39993
• CVE-2025-40240
• CVE-2025-68285

References

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