Junglewise Threat Intelligence

CVE-2026-64183: Linux Kernel NULL pointer dereference in EFI runtime workqueue allocation

CVE-2026-64183 · Severity: info · CVSS 0 · Published 2026-07-19

Technologies: Linux Kernel. Vendors: Linux.

Executive brief

A vulnerability was identified in the Linux kernel where the system could crash during the boot process. This occurs because certain power management and configuration tasks (ACPI) try to use system firmware services (EFI) before they are fully initialized. This results in a system failure (NULL pointer dereference) that prevents the operating system from starting correctly.

Technical details

The vulnerability is a NULL pointer dereference within the EFI subsystem of the Linux kernel. It is caused by an initialization order dependency where ACPI PRM handlers, which are delegated to an EFI runtime workqueue, may be invoked during 'subsys_initcall' before 'efisubsys_init' has allocated the required workqueue. An attacker with local access could potentially exploit this timing issue to cause a Denial of Service (system crash). The fix involves moving the EFI workqueue allocation to an earlier 'postcore_initcall' phase to ensure availability for ACPI.

Affected products

  • Linux Linux Kernel 6.6 to 6.6.142, 6.12 to 6.12.92, 6.18 to 6.18.34, 7.0 to 7.0.11

Timeline

  • 2026-05-19: patched: Initial fix authored by Ard Biesheuvel
  • 2026-07-19: disclosed: CVE-2026-64183 published

References

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