KVM: x86: Ensure vendor's exit handler runs before fastpath userspace exits
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · High · High
- Fix status
- Partial Red Hat: 3 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Ensure vendor's exit handler runs before fastpath userspace exits Move the handling of fastpath userspace exits into vendor code to ensure KVM runs vendor specific operations that need to run before userspace gains control of the vCPU. E.g. for VMX (and soon to be for SVM as well), KVM needs to flush the PML buffer prior to exiting to userspace, otherwise any memory written by the final KVM_RUN might never be flagged as dirty. Note, waiting to snapshot CR0 and CR3 until svm_handle_exit() is flawed in general, as that risks consuming stale state in a fastpath handler. That will be addressed in a future change.
Why it matters now
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
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 6.12 and later | 6.12.96, 6.18.39, 7.1.4, 7.2 | Patch available | CNA |
- Linux VendorLinux Affected 6.12 and later Fixed in 6.12.96, 6.18.39, 7.1.4, 7.2 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 6.12 to before 6.12.96; 6.13 to before 6.18.39; 6.19 to before 7.1.4 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 6.12 to before 6.12.96; 6.13 to before 6.18.39; 6.19 to before 7.1.4 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.12.96, 6.18.39, 7.1.4, 7.2
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Not affected: 3 products
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2026-64284
- 2026-10-03 Alias added: GHSA-gv38-jcpj-j76h
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-20 Weakness changed · CISA ADP
- 2026-10-29 Affected versions changed · Red Hat
References
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2026-64284 · CVE Program
- CVE-2026-64284 · NVD
- FIRST EPSS
- GHSA-gv38-jcpj-j76h · GitHub Advisory Database · CC BY 4.0
- CVE-2026-64284 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences