CVE-2026-89970
Description
A flaw was found in the nvmet-auth component of the Linux kernel. A timing issue during the cleanup of a Submission Queue (SQ) can lead to a use-after-free vulnerability. This occurs when a delayed authentication task attempts to access memory that has already been released or repurposed. An attacker could potentially exploit this to cause a system crash (denial of service) or other memory corruption impacts.
Statement
This vulnerability is rated as an Important severity flaw because an exploitable use-after-free condition within the kernel memory space can lead to denial of service through system crashes or potentially local privilege escalation. In standard Red Hat Enterprise Linux installations, the NVMe over Fabrics target subsystem is neither loaded nor configured by default, significantly limiting the exposure to systems designated as NVMe-oF storage targets. Exploitation is further confined to environments configured with in-band authentication during queue teardown operations.
Mitigation
Prevent the NVMe target kernel module from loading if the host is not intended to operate as an NVMe over Fabrics target server.
1. Create a modprobe configuration file to disable the module:
# echo "install nvmet /bin/true" > /etc/modprobe.d/disable-nvmet.conf
2. If the module is already loaded, remove it:
# modprobe -r nvmet
Caveats: This configuration prevents the host from functioning as an NVMe-oF target. It does not disrupt normal NVMe host/initiator storage capabilities.
Warning: If the nvmet module is currently in use, removing it or restarting the host will terminate existing NVMe target storage connections and disrupt attached clients.
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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.8 | N/A | 9.8 |
| Attack Vector | Local | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
If the expired pointer is used in a read operation, an attacker might be able to control data read in by the application.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If the expired 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 expired pointer is used in a function call, or points to unexpected data in a write operation, then code execution may be possible.
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