RHSA-2026:3964 - 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: ipv6: BUG() in pskb_expand_head() as part of calipso_skbuff_setattr() (CVE-2025-71085)
• kernel: macvlan: fix possible UAF in macvlan_forward_source() (CVE-2026-23001)

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 - 2429026 - CVE-2025-71085 kernel: ipv6: BUG() in pskb_expand_head() as part of calipso_skbuff_setattr()
• BZ - 2432664 - CVE-2026-23001 kernel: macvlan: fix possible UAF in macvlan_forward_source()

CVEs

• CVE-2025-71085
• CVE-2026-23001

References

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