RHSA-2026:97521 - 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)

Bug Fix(es) and Enhancement(s):

• [RHEL 9] Update Intel CPU microcode to the latest version (JIRA:RHEL-240771)

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.

Additional Changes:

For detailed information on changes in this release, see the Red Hat Enterprise Linux 9 Release Notes linked from 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

Fixes

• BZ - 2514104 - CVE-2025-35973 kernel: hypervisor: Intel Processors: Privilege escalation in Ring 0 via improper value handling
• RHEL-240771 - [RHEL 9] Update Intel CPU microcode to the latest version

CVEs

• CVE-2025-35973

References

• https://access.redhat.com/security/updates/classification/#important
• https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/9/html/9.9_release_notes/index