CVE-2026-64456 Linux CVE debrief

Who should care

Linux system administrators, security teams, and developers using the affected hwrng: virtio component should assess exposure and prioritize remediation due to potential memory safety issues and cross-boundary leaks. The vulnerability can be triggered by a malicious or buggy virtio-rng backend, emphasizing the need for high-priority assessment and remediation for Linux systems using the affected hwrng: virtio component. Linux system administrators, and

Why it matters

The CVE-2026-64456 vulnerability in the Linux kernel's hwrng: virtio component requires high-priority assessment and remediation due to potential memory safety issues and cross-boundary leaks.

• Memory safety issues can occur due to reading past the end of the inline array into adjacent slab contents.
• Potential cross-boundary leaks may allow sensitive data exposure.
• Verification of system configurations and updates to unaffected versions is necessary.
• Remediation priority is high due to the potential for memory safety issues and data exposure.

Technical summary

The vulnerability is caused by the hwrng: virtio component not properly clamping the device-reported used.len at copy_data(), allowing a malicious or buggy virtio-rng backend to steer the memcpy() past the end of the inline array into adjacent kmalloc-1k slab bytes. This can lead to memory safety issues and potential cross-boundary leaks, emphasizing the need for high-priority assessment and remediation for Linux systems using the affected hwrng: virtio component. The vulnerability can be triggered by a and requires

Defensive priority

High-priority assessment and remediation recommended for Linux systems using the affected hwrng: virtio component.

Recommended defensive actions

• Assess exposure and prioritize remediation for Linux systems using the affected hwrng: virtio component
• Review and apply patches from Linux vendors
• Monitor for potential memory safety issues and cross-boundary leaks
• Verify system configurations and update to unaffected versions if necessary
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record and source item provide details on the vulnerability, including its description, affected versions, and references to source code changes. The Linux kernel's hwrng: virtio component is vulnerable to memory safety issues and potential cross-boundary leaks due to improper clamping of device-reported used.len at copy_data(). The vulnerability can be triggered by a malicious or buggy virtio-rng backend, emphasizing the need for high-priority assessment and remediation for Linux systems using the affected hwrng: virtio

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.