CVE-2026-23332
Description
A flaw was found in the Linux kernel's intel_pstate cpufreq driver. A local user can trigger a system crash, leading to a Denial of Service (DoS), by attempting to disable the CPU turbo feature through the sysfs interface. This vulnerability occurs on systems booted with specific kernel arguments like "nosmt" or "maxcpus", due to a NULL pointer dereference when processing offline CPUs.
Statement
This flaw affects Intel systems using the intel_pstate cpufreq driver when booted with nosmt or maxcpus boot parameters. Writing to /sys/devices/system/cpu/intel_pstate/no_turbo causes all_cpu_data[] to be dereferenced for offline CPUs, which have NULL entries. The crash requires sysfs write access, typically requiring root privileges.
Mitigation
Avoid modifying /sys/devices/system/cpu/intel_pstate/no_turbo on systems booted with nosmt or maxcpus parameters.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.5 | 5.5 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.
Integrity,Confidentiality
Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory
In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
