CVE-2026-98428
Description
A flaw was found in the Linux kernel's ALSA USB 6fire audio driver. The driver improperly embeds USB Request Blocks (URBs)—structures that manage USB communications—directly inside driver objects rather than allocating them dynamically. Because URBs rely on reference counting and can be released asynchronously, this design can cause memory to be accessed after it has been freed. A local attacker could exploit this flaw to cause a Denial of Service (DoS) via a system crash or potentially execute arbitrary code.
Statement
The ALSA USB 6fire driver embeds reference counted URBs inside PCM, MIDI, and communication runtime objects. An URB can remain referenced or be released asynchronously after the containing runtime object has been destroyed, resulting in a kernel use after free and possible memory corruption. A local process may help trigger the vulnerable lifetime transition by using the affected audio or USB device while disconnect, cleanup, or an error path races with URB completion. For the CVSS the PR:L value is used because practical software triggering requires a local user or process with access to the affected ALSA or USB device. The issue is not network reachable and requires the USB 6fire driver and compatible hardware to be present. Impact is at least a local denial of service via kernel crash and in the worst case may include confidentiality and integrity impact or privilege escalation because the underlying primitive is a kernel use after free. The asynchronous lifetime window makes exploitation complex and configuration dependent.
Mitigation
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
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)
Integrity
Technical Impact: Modify Memory
The use of previously freed memory may corrupt valid data, if the memory area in question has been allocated and used properly elsewhere.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If chunk consolidation occurs after the use of previously freed data, the process may crash when invalid data is used as chunk information.
Confidentiality
Technical Impact: Read Memory
Read operations on freed memory can sometimes leak sensitive information instead of causing a crash
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
If malicious data is entered before chunk consolidation can take place, it may be possible to take advantage of a write-what-where primitive to execute arbitrary code. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap data. If one of these function pointers is overwritten with an address to valid shellcode, execution of arbitrary code can be achieved.
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