Critical

Xen Hypervisor Flaws Let One Malicious VM Read and Write Any Other VM's Memory

The Hacker News

November 4, 2026 at 11:46 AM

Overview

Two significant vulnerabilities have been discovered in the Xen hypervisor that could allow a malicious virtual machine (VM) to access and manipulate the memory of other VMs on the same host, including the critical dom0 VM that manages them. This flaw affects all versions of Xen from 4.6 onward. Patches have been released to address these vulnerabilities, but the Xen Project has indicated that there is no known mitigation strategy available at this time. The ability for one VM to interact with another's memory poses serious security risks, particularly for cloud service providers and any organization relying on virtualization for their operations, as it could lead to unauthorized data access and potential breaches. Users and administrators should apply the patches as soon as possible to secure their environments.

Key Takeaways

Affected Systems: Xen hypervisor versions 4.6 and later
Action Required: Patches have been released; users should apply them immediately.
Timeline: Disclosed on November 3, 2023

Original Article Summary

Two flaws in the Xen hypervisor allow a malicious guest virtual machine (VM) to read and write the memory of other VMs on the same host, including dom0. Dom0 is the VM that, by default, has full permissions and manages the others. Patches are out, and there is no known mitigation, the Xen Project said in an advisory on November 3. All Xen versions from 4.6 onward are vulnerable,

Impact

Xen hypervisor versions 4.6 and later

Exploitation Status

No active exploitation has been reported at this time. However, organizations should still apply patches promptly as proof-of-concept code may exist.

Timeline

Disclosed on November 3, 2023

Remediation

Patches have been released; users should apply them immediately.

Additional Information

This threat intelligence is aggregated from trusted cybersecurity sources. For the most up-to-date information, technical details, and official vendor guidance, please refer to the original article linked below.

Related Topics: This incident relates to Vulnerability, Critical.

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