RHSA-2026:3268 - Security Advisory

Topic

An update for kernel is now available for Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support, Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions, and Red Hat Enterprise Linux 8.6 Telecommunications Update Service.

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 packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es):

• kernel: RDMA/core: Fix "KASAN: slab-use-after-free Read in ib_register_device" problem (CVE-2025-38022)
• kernel: Linux kernel: Memory corruption in Squashfs due to incorrect block size calculation (CVE-2025-38415)
• kernel: Linux kernel: Denial of Service in ATM CLIP module via infinite recursion (CVE-2025-38459)
• kernel: Linux kernel: Denial of Service via out-of-bounds read in USB configuration parsing (CVE-2025-39760)
• kernel: smb: client: let recv_done verify data_offset, data_length and remaining_data_length (CVE-2025-39933)
• kernel: Linux kernel: Use-after-free in proc_readdir_de() can lead to privilege escalation or denial of service. (CVE-2025-40271)
• kernel: ip6_vti: fix slab-use-after-free in decode_session6 (CVE-2023-53821)
• kernel: Linux kernel: Use-after-free in teql queueing discipline can lead to privilege escalation (CVE-2026-23074)

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 x86_64 - Extended Life Cycle Long Life 8.6 x86_64
• Red Hat Enterprise Linux Server - AUS 8.6 x86_64
• Red Hat Enterprise Linux Server - TUS 8.6 x86_64
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 8.6 ppc64le
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 8.6 x86_64
• Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle Long Life 8.6 aarch64
• Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle Long Life 8.6 ppc64le
• Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle Long Life 8.6 s390x

Fixes

• BZ - 2373326 - CVE-2025-38022 kernel: RDMA/core: Fix "KASAN: slab-use-after-free Read in ib_register_device" problem
• BZ - 2383404 - CVE-2025-38415 kernel: Linux kernel: Memory corruption in Squashfs due to incorrect block size calculation
• BZ - 2383487 - CVE-2025-38459 kernel: Linux kernel: Denial of Service in ATM CLIP module via infinite recursion
• BZ - 2394601 - CVE-2025-39760 kernel: Linux kernel: Denial of Service via out-of-bounds read in USB configuration parsing
• BZ - 2401432 - CVE-2025-39933 kernel: smb: client: let recv_done verify data_offset, data_length and remaining_data_length
• BZ - 2419837 - CVE-2025-40271 kernel: Linux kernel: Use-after-free in proc_readdir_de() can lead to privilege escalation or denial of service.
• BZ - 2420329 - CVE-2023-53821 kernel: ip6_vti: fix slab-use-after-free in decode_session6
• BZ - 2436791 - CVE-2026-23074 kernel: Linux kernel: Use-after-free in teql queueing discipline can lead to privilege escalation

CVEs

• CVE-2023-53821
• CVE-2025-38022
• CVE-2025-38415
• CVE-2025-38459
• CVE-2025-39760
• CVE-2025-39933
• CVE-2025-40271
• CVE-2026-23074

References

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