CVE-2026-62435Network attack vector

Guest-to-host escape via grant-table version-switch race

Published Jul 28, 2026 · Updated Jul 28, 2026

Race condition in Xen 4.0 and later allows guest OS users to escape to the host through concurrent grant-table version switching. Grant-table paths drop and reacquire the grant-table lock yet retain assumptions about the valid reference limit while another vCPU switches from v1 to v2. Exploitation requires a multi-vCPU x86 guest allowed to use grant-table v2 and grants host privilege escalation, information disclosure, or a service interrupt of an unspecified form.

CVSS severity6.5
Medium
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in Xen 4.0 and later allows guest OS users to escape to the host through concurrent grant-table version switching. Grant-table paths drop and reacquire the grant-table lock yet retain assumptions about the valid reference limit while another vCPU switches from v1 to v2. Exploitation requires a multi-vCPU x86 guest allowed to use grant-table v2 and grants host privilege escalation, information disclosure, or a service interrupt of an unspecified form.

The record

CVE
CVE-2026-62435
Published
Jul 28, 2026
Updated
Jul 28, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-362, T1068
Attack vector
network
Privileges
unauthenticated

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 vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5CISA ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L

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

Weakness, pattern, technique

CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
T1068Exploitation for Privilege Escalation

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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