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Misplaced check in Xen grant copy allows out-of-scope memory access

Priority LOW 19CWE-693Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
Low · Low · None
Fix status
No fix listed

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-693.

Summary

The Xen hypervisor's grant copy operation is affected. The check that limits copying by frame number to the caller's own memory is misplaced, a protection mechanism failure (CWE-693). A local attacker with low privileges can affect the confidentiality and integrity of data they should not reach.

Written with Claude Haiku 5.5 from the sources below · 2026-11-05

Description from the CNA

[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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00143 3rd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
XenXen——No fix listedCNA
  • Xen VendorXen Affected — Fixed in — No fix listed CNA

Remediation

The sources list no fixed version for Xen.

Written with Claude Haiku 5.5 from the sources below · 2026-11-05

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-11-04 Threatist record created from CVE-2026-102704
  2. 2026-11-04 Alias added: GHSA-5425-5qfw-cm7h
  3. 2026-11-04 CVSS score added · CISA ADP
  4. 2026-11-04 Weakness changed · CISA ADP
  5. 2026-11-04 CISA SSVC decision points changed
  6. 2026-11-05 Affected versions changed · Red Hat
  7. 2026-11-05 CVSS score added · Red Hat

References

  • TI-2012-00210 The x86-64 kernel system-call functionality in Xen 4.1.2 and earlier, as used in Citrix… CVSS 2.0HIGH 7.2
  • TI-2023-07042 Information disclosure through error messages in AMD Ryzen™ 3000 Series Desktop… CVSS 3.1MEDIUM 5.5
  • TI-2015-04333 The C+ mode offload emulation in the RTL8139 network card device model in QEMU, as used… CVSS 2.0HIGH 9.3
  • TI-2015-06741 The KVM subsystem in the Linux kernel through 4.2.6, and Xen 4.3.x through 4.6.x, allows… CVSS 3.1CRITICAL 10.0
  • TI-2018-06436 A statement in the System Programming Guide of the Intel 64 and IA-32 Architectures… CVSS 3.0HIGH 7.8
  • TI-2024-20522 x86: Incorrect logic for BTC/SRSO mitigations CVSS 3.1HIGH 7.5
See all 541 →

Sources