RHSA-2026:97521: Important: microcode_ctl security, bug fix, and enhancement update
The microcodectl 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.
Affected Software
Event History
Frequently Asked Questions
Which systems are covered by this update?
The advisory applies to Red Hat microcode_ctl packages and specifically notes an Intel CPU microcode update for RHEL 9. The package provides microcode updates for both Intel and AMD processors, but the listed security fix concerns Intel processors.
What access does an attacker need to exploit the listed security issue?
The issue is described as a privilege escalation in Ring 0 on Intel processors through improper value handling in the hypervisor. The advisory does not state the required initial access level, affected hypervisor configurations, or whether exploitation is possible under default settings.
How can I determine whether my environment is affected?
Check whether affected systems use Intel processors, run RHEL 9, and have the microcode_ctl package installed. The advisory does not provide affected or fixed microcode_ctl version numbers, so version-level determination is not possible from the provided information.