Read the docs

Multiple flaws in Xen GNTTABOP_cache_flush handling

Priority LOW 39CWE-191Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-191 and the CVSS impact.

Summary

Xen's GNTTABOP_cache_flush grant table operation has two issues. A calculation introduced by an earlier fix for overflows can underflow (CWE-191), causing a loop that takes excessively long on 64-bit Arm and would likely eventually crash the hypervisor. Guests can also issue invalidate-without-clean cache flushes against read-only grant mappings from another domain, which may corrupt the granted memory.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Description from the CNA

[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] 1) XSA-437 (CVE-2023-34321) addressed issues with overflows in calculations involved in guests flushing caches through GNTTABOP_cache_flush. Unfortunately the fix there introduced a calculation which may underflow, resulting in a loop which would - at least on 64-bit Arm - take excessively long, and which would likely eventually crash the hypervisor. This is CVE-2026-102699. 2) GNTTABOP_cache_flush may be issued on memory mapped from another domain using the grant table interface. However there was no restriction to disallow the use of invalidate-without-clean against read-only grant mappings, which may corrupt the granted memory. This is CVE-2026-102702.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00292 21st 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
Yes
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 · 2026-11-06

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-13 Threatist record created from CVE-2026-102702
  2. 2026-10-13 Alias added: GHSA-p4h6-6vf5-jwcw
  3. 2026-10-20 CVSS score added · CISA ADP
  4. 2026-10-20 Weakness changed · CISA ADP
  5. 2026-10-20 CISA SSVC decision points changed
  6. 2026-11-06 Affected versions changed · Red Hat
  7. 2026-11-06 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