CVE-2026-99230
Description
A flaw was found in the Linux kernel's io_uring subsystem. When cancelable commands are removed, recycled request objects can retain stale list pointers instead of being cleanly reinitialized. A local attacker can trigger this issue by submitting specific asynchronous I/O requests, causing the kernel to dereference invalid memory. This flaw leads to a system crash, resulting in a Denial of Service (DoS).
Statement
This vulnerability is classified as Moderate severity for Red Hat because successful exploitation requires local access and solely impacts system availability through an unexpected kernel crash. The issue stems from improperly reinitialized request tracking nodes within the kernel's io_uring asynchronous subsystem, causing invalid pointer dereferences when specific vectored operations interact with recycled commands. Exploitation cannot be triggered remotely and does not enable privilege escalation or data confidentiality loss, limiting the impact to a local denial of service.
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)
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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