CVE-2026-79602

Host crash via mishandled HVM emulation return code

Published Sep 8, 2026 · Updated Sep 8, 2026

Denial of service in Xen 4.6 and later allows guest OS users to crash the entire x86 host through HVM PCI I/O emulation. The x86 HVM emulator mishandles a return code while processing I/O for an assigned PCI device with an I/O-port BAR and reaches a BUG(). An unprivileged HVM guest must have such a device assigned; Arm hosts and guests without I/O BAR passthrough are not affected.

CVSS severity6.5
Medium
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Xen 4.6 and later allows guest OS users to crash the entire x86 host through HVM PCI I/O emulation. The x86 HVM emulator mishandles a return code while processing I/O for an assigned PCI device with an I/O-port BAR and reaches a BUG(). An unprivileged HVM guest must have such a device assigned; Arm hosts and guests without I/O BAR passthrough are not affected.

The record

CVE
CVE-2026-79602
Published
Sep 8, 2026
Updated
Sep 8, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-252, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 8, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5SUSECVSS: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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-252Unchecked Return Value
T1499.004Application or System Exploitation

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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