CVE-2026-31466 Linux CVE debrief

Who should care

Linux kernel users and administrators should be aware of this vulnerability and take necessary actions to patch their systems. This vulnerability can be exploited locally with low privileges, and its successful exploitation can lead to a denial of service. System administrators and security teams should prioritize patching and verifying system configurations to prevent potential exploitation.

Technical summary

The vulnerability is caused by a missing memory barrier in the softleaf_to_folio() function, which can lead to a race condition between folio split and zap_nonpresent_ptes(). The vulnerability can be exploited locally with low privileges, and its successful exploitation can lead to a denial of service. The vulnerability has been resolved by adding a missing smp_rmb() in softleaf_to_folio() and softleaf_to_page(). Affected Linux kernel users should apply patches or mitigations to prevent potential exploitation.

Defensive priority

Medium-High due to local exploitability and potential for denial of service. Linux kernel users should prioritize patching and verifying system configurations to prevent potential exploitation. Additional monitoring and verification steps may be required to confirm exposure and ensure system security. Compensating controls, such as monitoring and asset inventory, may be necessary for exposed systems while remediation is scheduled and verified. Rollback/change windows and source tracking may also be necessary to ensure system security and prevent potential exploitation. System administrators and security teams should review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance, and plan vendor-supported updates or mitigations through normal change control where exposure is confirmed. They should also review compensating controls for exposed systems while remediation is scheduled and verified, and check relevant monitoring, detection, and logs for exposed assets that need extra review. Exceptions, retest remediated assets, and close the item only after evidence is documented. Track exceptions and retest remediated assets to ensure system security and prevent potential exploitation. This vulnerability requires immediate attention from Linux kernel users and administrators to prevent potential exploitation and ensure system security. The vulnerability has been resolved by the Linux kernel maintainers, and patches are available for affected systems. Linux kernel users should apply patches or mitigations as necessary to prevent potential exploitation and ensure system security. Additional verification steps may be required to confirm exposure and ensure system security. Compensating controls, such as monitoring and asset inventory, may be necessary for exposed systems while remediation is scheduled and verified. Rollback/change windows and source tracking may also be necessary to ensure system security and prevent potential exploitation. System administrators and security teams should prioritize patching and verifying system configurations to prevent potential exploitation and ensure system security. The vulnerability

Recommended defensive actions

• Apply the official patches provided by the Linux kernel maintainers.
• Ensure that the Linux kernel is updated to a version that includes the fix.
• Monitor system logs for potential exploitation attempts.
• Review system configurations to ensure that the Linux kernel is properly patched.
• Verify that compensating controls are in place for exposed systems.
• Track exceptions and retest remediated assets to ensure system security.
• Perform regular asset inventory to identify potential vulnerabilities.

Evidence notes

The vulnerability was reported by a researcher and has been resolved by the Linux kernel maintainers. The vulnerability affects multiple versions of the Linux kernel, including 4.5, 5.11, 5.16, 6.2, 6.7, and 6.13. Linux kernel users should verify their system configurations and apply patches or mitigations as necessary. Additional verification steps may be required to confirm exposure and ensure system security.

Official resources