CVE-2026-0665: Qemu-kvm: heap off-by-one in kvm xen physdevop_map_pirq

Published Jan 12, 2026
·
Updated

An off-by-one error was found in QEMU's KVM Xen guest support. A malicious guest could use this flaw to trigger out-of-bounds heap accesses in the QEMU process via the emulated Xen physdev hypercall interface, leading to a denial of service or potential memory corruption.

Affected Software

1 affected component
Qemu Qemu

Event History

Jan 12, 2026
Data Sourced
via Red Hat·10:48 AM
DescriptionSeverityAffected Software
Feb 18, 2026
CVE Published
via MITRE·08:50 PM
Data Sourced
via MITRE·08:50 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·09:16 PM
DescriptionSeverityWeakness
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Frequently Asked Questions

1

What is the severity of CVE-2026-0665?

CVE-2026-0665 is rated as a high severity vulnerability due to its potential for denial of service and memory corruption.

2

How do I fix CVE-2026-0665?

To fix CVE-2026-0665, update to the latest version of QEMU that addresses this vulnerability.

3

What causes CVE-2026-0665?

CVE-2026-0665 is caused by an off-by-one error in QEMU's KVM Xen guest support leading to out-of-bounds heap accesses.

4

What can an attacker do with CVE-2026-0665?

An attacker can exploit CVE-2026-0665 to trigger denial of service or potentially corrupt memory in the QEMU process.

5

Is CVE-2026-0665 specific to certain versions of QEMU?

CVE-2026-0665 affects all versions of QEMU prior to the fix for this vulnerability, so it's important to check your version.

Company

Resources

Contact

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CVE-2026-0665 - Qemu-kvm: heap off-by-one in kvm xen physdevop_map_pirq - SecAlerts