RHSA-2026:27719 - Security Advisory

Topic

An update for kernel is now available for Red Hat Enterprise Linux 6 Extended Lifecycle Support - EXTENSION.

Red Hat Product Security has rated this update as having a security impact of Critical. 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: ip6_tunnel: clear skb2->cb[] in ip4ip6_err() (CVE-2026-43037)
• kernel: Linux kernel: smb: client: reject userspace cifs.spnego descriptions (CVE-2026-46243)

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 Server - Extended Life Cycle Support Extension 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension (for IBM z Systems) 6 s390x

Fixes

• BZ - 2464351 - CVE-2026-43037 kernel: ip6_tunnel: clear skb2->cb[] in ip4ip6_err()
• BZ - 2481486 - CVE-2026-46243 kernel: Linux kernel: smb: client: reject userspace cifs.spnego descriptions

CVEs

• CVE-2026-43037
• CVE-2026-46243

References

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