Improper Check for Unusual or Exceptional Conditions in Linux kernel - CVE-2026-64214
Published: July 27, 2026
Vulnerability identifier: #VU139781
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-64214
CWE-ID: CWE-754
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to improper access of per-CPU preemption state in arch_irq_work_raise() when handling machine check exceptions in real mode. A local user can trigger a machine check exception that reaches arch_irq_work_raise() to cause a denial of service.
The issue occurs in NMI context on powerpc systems, where accessing preempt_count from real mode can fault and panic the kernel.
How to mitigate CVE-2026-64214
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/31467b23823ffec1f6fff407f8e3ca9af8b7491a
- https://git.kernel.org/stable/c/51860e423592893cd7bfa7287d99a3aff4dc3a9d
- https://git.kernel.org/stable/c/6dcd072a5ae3aed336e4a67a7d4cc5205b240065
- https://git.kernel.org/stable/c/72d8d1c36452a4d3ee134b1da48de7518c1329f9
- https://git.kernel.org/stable/c/8079acc5ee5235a627e4586d4f42082a9000ea64
- https://git.kernel.org/stable/c/a09d07ac45e283c9861a9ceea06f56d0ba851d22