CVE 2026 74580

A flaw was found in the Linux kernel's vhost subsystem. A local attacker could exploit this vulnerability by reconfiguring a virtual ring (vring) using specific ioctl commands while a device Input/Output Memory Management Unit (IOTLB) is attached. This improper handling of the vring metadata cache can lead to out-of-bounds memory access, potentially resulting in information disclosure, data corruption, or a denial of service.

Prevent the vhost kernel module from loading on systems where kernel-accelerated virtio is not required.

1. Add a configuration entry in /etc/modprobe.d to disable autoloading: # echo "install vhost /bin/true" > /etc/modprobe.d/disable-vhost.conf

2. If the module is already loaded and no guests are using it, unload the vhost drivers: # modprobe -r vhost_net vhost_vsock vhost_scsi vhost

Caveats: Disabling vhost prevents in-kernel acceleration for virtio networking, storage, and vsock communication, which may degrade I/O performance or cause virtual machine instances dependent on vhost devices to fail to start.

Warning: A system reboot or stopping active virtual machines is required if the driver is currently loaded and actively in use.

Bugzilla 2521055 : kernel: vhost: reset the vring metadata cache on vring reconfiguration

CWE-825 : Expired Pointer Dereference

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: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:H

cve.org: CVSS:3.1 / AV:L / AC:L / PR:L / UI:N / S:C / C:H / I:H / A:H

Understanding the Weakness (CWE)

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.

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.

Frequently Asked Questions

"Under investigation" doesn't necessarily mean that the product is affected by this vulnerability. It only means that our Analysis Team is still working on determining whether the product is affected and how it is affected.

The term 'Affected' means that our Analysis team has determined that this product, such as Red Hat Enterprise Linux 8 or OpenShift Container Platform 4, is affected by this vulnerability and a fix may be released to address this issue in the near future. This includes all minor releases of this product unless noted otherwise in the Statement text.

Upgrade to a supported product version that includes a fix for this vulnerability (recommended).

Apply a mitigation (if one exists).

Customers with the Technical Account Manager (TAM) RHEL Security Select Add-on can review this CVE directly with their TAM.

Apply a mitigation (if one exists).

Red Hat Engineering focuses on addressing high-priority issues based on the impact and product lifecycle expectations. Therefore, lower-priority issues will not receive immediate fixes.

Customers with the technical account manager (TAM) RHEL Security Select Add-on can review this CVE directly with their TAM.

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