CVE-2026-99219
Description
A flaw was found in the Linux kernel's ftrace (function tracing) subsystem. This vulnerability allows a local user to cause a Denial of Service (DoS) by crashing the system. The issue occurs when reading tracing filter information while a kernel module is simultaneously loaded or unloaded, causing the kernel to dereference uninitialized memory following a failed symbol lookup.
Statement
This vulnerability is rated as Moderate severity because it requires local access and precise timing during concurrent kernel module operations to induce a system crash. In typical Red Hat deployments, access to the kernel tracing pseudo-filesystem is restricted to administrative users, significantly reducing exposure to unprivileged accounts. Additionally, the flaw only leads to a local denial of service without exposing sensitive information or enabling unauthorized privilege escalation.
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 | 4.7 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | High | 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:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
If the uninitialized pointer is used in a read operation, it might not point to a valid memory location. An attacker might be able to read sensitive portions of memory.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If the uninitialized pointer references a memory location that is not accessible to the product, or points to a location that is "malformed" (such as NULL) or larger than expected by a read or write operation, then a crash may occur.
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
If the uninitialized pointer is used in a function call, or points to unexpected data in a write operation, then code execution may be possible. If the uninitialized pointer is used as a function call, then arbitrary functions could be invoked.
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