RHSA-2026:68011 - Security Advisory

Topic

An update for microcode_ctl is now available for Red Hat Enterprise Linux 9.

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 microcode_ctl packages provide microcode updates for Intel and AMD processors.

Security Fix(es):

• kernel: hypervisor: Intel Processors: Privilege escalation in Ring 0 via improper value handling (CVE-2025-35973)
• kernel: microcode_ctl: Intel Xeon 6 Processors: Privilege escalation via improper memory range handling in SMM (CVE-2025-31936)

Bug Fix(es) and Enhancement(s):

• [RHEL 9.8.z] Update Intel CPU microcode to the latest version (JIRA:RHEL-260496)

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

Affected Products

• Red Hat Enterprise Linux for x86_64 9 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 9.8 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.8 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 9.8 x86_64

Fixes

• BZ - 2514104 - CVE-2025-35973 kernel: hypervisor: Intel Processors: Privilege escalation in Ring 0 via improper value handling
• BZ - 2514115 - CVE-2025-31936 kernel: microcode_ctl: Intel Xeon 6 Processors: Privilege escalation via improper memory range handling in SMM
• RHEL-260496 - [RHEL 9.8.z] Update Intel CPU microcode to the latest version

CVEs

• CVE-2025-31936
• CVE-2025-35973

References

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