CVE-2026-62427

Host denial of service via unfair platform-op locking

Published Jul 28, 2026 · Updated Jul 28, 2026

Denial of service in Xen 4.0 and later allows guest OS users to stall the entire host through repeated platform operations. The platform-op path acquires a non-fair system-wide lock and, with XSM/Flask, can take it before checking the caller's permission. A less-privileged domain that can issue platform operations can monopolize the lock, delaying equally or more privileged domains and interrupting the host.

CVSS severity8.8
High
EPSS probability0.24%
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 4.0 and later allows guest OS users to stall the entire host through repeated platform operations. The platform-op path acquires a non-fair system-wide lock and, with XSM/Flask, can take it before checking the caller's permission. A less-privileged domain that can issue platform operations can monopolize the lock, delaying equally or more privileged domains and interrupting the host.

The record

CVE
CVE-2026-62427
Published
Jul 28, 2026
Updated
Jul 28, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-284, CWE-305, T1499.004
Attack vector
Unavailable
Privileges
Unavailable

Timeline

How it unfolded

  1. Jul 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 28, 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 vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
VectorUnavailable
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-284Improper Access Control
CWE-305Authentication Bypass by Primary Weakness
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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