CVE-2026-0665

Guest-triggered host crash via PIRQ bounds error

Published Feb 18, 2026 · Updated Feb 18, 2026

Out-of-bounds heap access in QEMU 8.0.0 through 10.2.0 allows guest OS users to crash the host QEMU process via a Xen physdev hypercall. xen_physdev_map_pirq uses a strict greater-than bounds check, accepting a PIRQ equal to the allocated PIRQ count and permitting an out-of-bounds heap access. The path requires Linux/KVM Xen guest mode with xen-version enabled; the established impact is a host-process crash, with potential memory corruption also reported.

CVSS severity6.5
Medium
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds heap access in QEMU 8.0.0 through 10.2.0 allows guest OS users to crash the host QEMU process via a Xen physdev hypercall. xen_physdev_map_pirq uses a strict greater-than bounds check, accepting a PIRQ equal to the allocated PIRQ count and permitting an out-of-bounds heap access. The path requires Linux/KVM Xen guest mode with xen-version enabled; the established impact is a host-process crash, with potential memory corruption also reported.

The record

CVE
CVE-2026-0665
Published
Feb 18, 2026
Updated
Feb 18, 2026
Vendor
QEMU Project
Product
QEMU
Classifications
CWE-787, T1499
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Feb 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 18, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=8.0.0 <=10.2.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

QEMU Project · QEMUversion=8.0.0 <=10.2.0

Published CVSS scores

6.5Fedora ProjectCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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