CVE-2026-0665
Received Received - Intake
Off-by-One Heap Overflow in QEMU KVM Xen Causes DoS

Publication date: 2026-02-18

Last updated on: 2026-02-18

Assigner: Fedora Project

Description
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.
CVSS Scores
EPSS Scores
Probability:
Percentile:
Meta Information
Published
2026-02-18
Last Modified
2026-02-18
Generated
2026-06-16
AI Q&A
2026-02-18
EPSS Evaluated
2026-06-15
NVD
CVE-2026-0665
EUVD
EUVD-2026-7934
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
qemu qemu *
Helpful Resources
Exploitability
CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-787 The product writes data past the end, or before the beginning, of the intended buffer.
Attack-Flow Graph
AI Quick Actions
Instant insights powered by AI
Executive Summary

[{'type': 'paragraph', 'content': "CVE-2026-0665 is a medium severity security vulnerability caused by an off-by-one error in QEMU's KVM Xen guest support, specifically in the PHYSDEVOP_map_pirq hypercall interface."}, {'type': 'paragraph', 'content': 'This flaw allows a malicious guest virtual machine to trigger out-of-bounds heap accesses in the QEMU process by exploiting the emulated Xen physdev hypercall interface.'}, {'type': 'paragraph', 'content': 'Such out-of-bounds accesses can lead to denial of service or potential memory corruption.'}] [1]

Impact Analysis

If exploited, this vulnerability can cause denial of service by crashing the QEMU process.

There is also a risk of memory corruption, which could potentially be leveraged for further attacks or system instability.

The vulnerability affects all hardware running Linux operating systems with QEMU-KVM when using Xen guest support.

Compliance Impact

I don't know

Detection Guidance

I don't know

Mitigation Strategies

I don't know

Chat Assistant
Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-0665. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70
EPSS Chart