CVE-2026-62430 - Vulnerability Details - OpenCVE

Accesses to the CMOS memory contents are done using an indirect IO port
pair. Therefore Xen needs to cache the guest chosen index, and one of
the usages of the index didn't take the necessary locking to avoid
concurrent changes. As a result, a guest could change the index after
it being checked, causing a subsequent out-of-bound read access to the
contents of an array.

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact None

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Exploitation none

Automatable yes

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Xen

Xen

unknown

Version	Status	Constraints
`consult Xen advisory XSA-503`	unknown	—

No data.

No data.

No data.

Project Subscriptions

No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

Running only PV or PVH guests will avoid the vulnerability.

References

Link	Providers
https://xenbits.xenproject.org/xsa/advisory-503.html

History

Tue, 28 Jul 2026 16:15:00 +0000

Type	Values Removed	Values Added
Description		Accesses to the CMOS memory contents are done using an indirect IO port pair. Therefore Xen needs to cache the guest chosen index, and one of the usages of the index didn't take the necessary locking to avoid concurrent changes. As a result, a guest could change the index after it being checked, causing a subsequent out-of-bound read access to the contents of an array.
Title		x86: Out-of-bounds read in vRTC emulation
Weaknesses		CWE-362
References		https://xenbits.xenproject.org/xsa/advisory-503.html
Metrics		cvssV3_1 `{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'}` ssvc `{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Projects

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MITRE

Status: PUBLISHED

Assigner: XEN

Published: 2026-07-28T12:32:33.150Z

Updated: 2026-07-28T16:33:30.367Z

Reserved: 2026-07-14T10:28:12.655Z

Link: CVE-2026-62430

Vulnrichment

Updated: 2026-07-28T16:33:30.367Z

NVD

No data.

Redhat

No data.

OpenCVE Enrichment

No data.

Weaknesses

CWE-362

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