RHSA-2026:95721 - Security Advisory

Topic

An update for kernel-rt is now available for Red Hat Enterprise Linux 7 Extended Lifecycle Support.

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: netfilter: nfnetlink_cthelper: fix OOB read in nfnl_cthelper_dump_table() (CVE-2026-43450)
• kernel: Bluetooth: hci_event: fix potential UAF in SSP passkey handlers (CVE-2026-46056)
• kernel: procfs: fix missing RCU protection when reading real_parent in do_task_stat() (CVE-2026-46259)
• kernel: dm cache policy smq: fix missing locks in invalidating cache blocks (CVE-2026-53062)
• kernel: ipv6: exthdrs: refresh nh pointer after ipv6_hop_jumbo() (CVE-2026-63924)
• kernel: ipv6: exthdrs: refresh nh after handling HAO option (CVE-2026-63922)
• kernel: ipv6: validate extension header length before copying to cmsg (CVE-2026-63920)
• kernel: selinux: check connect-related permissions on TCP Fast Open (CVE-2026-72243)
• kernel: ipv4: validate checksum_start before completing checksum (CVE-2026-99999)
• kernel: ZDI-CAN-33367: Linux Kernel skbuff skb_zerocopy Improper Ownership Management Local Privilege Escalation Vulnerability ()

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.

Red Hat recommends treating all kernel errata as security-relevant. Given the kernel's fundamental role, any bug has a higher chance of impacting system security, even if that impact only becomes clear after a fix is published. Therefore, Red Hat prioritizes delivering fixes that improve our customers' overall security posture.

Because of this proactive approach, a patch may be associated with a CVE assignment at a future date. Retroactive CVE assignments are always documented in the corresponding errata and on Red Hat's CVE pages. We strongly advise against delaying updates, as doing so may leave your system exposed when protections are already available.

Affected Products

• Red Hat Enterprise Linux for Real Time for x86_64 - Extended Life Cycle Support 7 x86_64

Fixes

• BZ - 2468228 - CVE-2026-43450 kernel: netfilter: nfnetlink_cthelper: fix OOB read in nfnl_cthelper_dump_table()
• BZ - 2482181 - CVE-2026-46056 kernel: Bluetooth: hci_event: fix potential UAF in SSP passkey handlers
• BZ - 2484477 - CVE-2026-46259 kernel: procfs: fix missing RCU protection when reading real_parent in do_task_stat()
• BZ - 2492278 - CVE-2026-53062 kernel: dm cache policy smq: fix missing locks in invalidating cache blocks
• BZ - 2502326 - CVE-2026-63924 kernel: ipv6: exthdrs: refresh nh pointer after ipv6_hop_jumbo()
• BZ - 2502327 - CVE-2026-63922 kernel: ipv6: exthdrs: refresh nh after handling HAO option
• BZ - 2502330 - CVE-2026-63920 kernel: ipv6: validate extension header length before copying to cmsg
• BZ - 2516684 - CVE-2026-72243 kernel: selinux: check connect-related permissions on TCP Fast Open
• BZ - 2553429 - CVE-2026-99999 kernel: ipv4: validate checksum_start before completing checksum
• BZ - 2559835 - kernel: ZDI-CAN-33367: Linux Kernel skbuff skb_zerocopy Improper Ownership Management Local Privilege Escalation Vulnerability

CVEs

• CVE-2026-43450
• CVE-2026-46056
• CVE-2026-46259
• CVE-2026-53062
• CVE-2026-63920
• CVE-2026-63922
• CVE-2026-63924
• CVE-2026-72243
• CVE-2026-99999

References

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