CVE-2026-102703

arbitrary read/write via grant copy

Published Nov 4, 2026 CVSS 3.1 · 4.4 Medium EPSS < 1% KEV · Not listed
Description
[This CNA information record relates to multiple CVEs; the
text explains which aspects/vulnerabilities correspond to which CVE.]

A common access pattern is a batch of Grant Copy operations acting on
adjacent address ranges in the same source or destination page. For
performance reasons, Xen caches details internally to reuse already
validated data. The conditions on when to re-validate the internal data
were not correct in some cases:

- Frame numbers and grant references could wrongly be mixed up. This
is CVE-2026-102703.

- Copying by frame number (rather than grant reference) is permitted
only when operating on the caller's own memory. The check to enforce
this restriction was misplaced. This is CVE-2026-102704.

Remediation

Vendor Workaround

There is no known mitigation.

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4818-1 xen security update
Debian DLA Debian DLA DLA-4881-1 xen security update
History
Type Values Removed Values Added
Weaknesses CWE-250
CWE-284
Type Values Removed Values Added
Weaknesses CWE-704
Metrics cvssV3_1

{'score': 4.4, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Xen
Xen xen
Vendors & Products Xen
Xen xen
Type Values Removed Values Added
Weaknesses CWE-250
CWE-284
Type Values Removed Values Added
Description [This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] A common access pattern is a batch of Grant Copy operations acting on adjacent address ranges in the same source or destination page. For performance reasons, Xen caches details internally to reuse already validated data. The conditions on when to re-validate the internal data were not correct in some cases: - Frame numbers and grant references could wrongly be mixed up. This is CVE-2026-102703. - Copying by frame number (rather than grant reference) is permitted only when operating on the caller's own memory. The check to enforce this restriction was misplaced. This is CVE-2026-102704.
Title arbitrary read/write via grant copy
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
XEN
Published
Updated
Nov 4, 2026, 6:24 PM
Reserved
Sep 29, 2026, 4:11 PM
Status
Undergoing Analysis
Published
Nov 4, 2026, 11:17 AM
Modified
Nov 6, 2026, 7:36 PM