Multiple flaws in Xen GNTTABOP_cache_flush handling
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
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
Remediation
The sources list no fixed version for Xen.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Vendor assessments
Timeline
- 2026-10-13 Threatist record created from CVE-2026-102702
- 2026-10-13 Alias added: GHSA-p4h6-6vf5-jwcw
- 2026-10-20 CVSS score added · CISA ADP
- 2026-10-20 Weakness changed · CISA ADP
- 2026-10-20 CISA SSVC decision points changed
- 2026-11-06 Affected versions changed · Red Hat
- 2026-11-06 CVSS score added · Red Hat
References
More Xen vulnerabilities
- 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
Sources
- CVE-2026-102702 · CVE Program
- CVE-2026-102702 · NVD
- FIRST EPSS
- GHSA-p4h6-6vf5-jwcw · GitHub Advisory Database · CC BY 4.0
- CVE-2026-102702 · Red Hat security data · CC BY 4.0
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