CVE-2026-99160
Description
A flaw was found in the Linux kernel's ring buffer subsystem. A local user can exploit this vulnerability to cause a Denial of Service (DoS) by crashing the kernel. The issue occurs when reading ring buffer metadata files for a central processing unit (CPU) that has never come online, resulting in a null pointer dereference.
Statement
This vulnerability is rated as Moderate impact because triggering it requires local access to the kernel tracing filesystem and results only in a system crash without permitting data disclosure or privilege escalation. In default Red Hat Enterprise Linux deployments, access to the tracefs hierarchy is restricted to privileged accounts, significantly limiting exposure to unprivileged users. Additionally, the issue only affects systems configured with possible CPU capacities where specific cores have never been brought online.
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 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | Low | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: 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.
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