Linux kernel VFIO affects virtualization hosts and cloud infrastructure; exploit can lead to host compromise and impacts many organizations running KVM/QEMU.
CVE-2026-64042
Linux vfio/pci DMABUF may expose unreserved PCI BARs enabling host compromise.
Is CVE-2026-64042 being exploited?
Not confirmed. CVE-2026-64042 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.15% probability of exploitation in the next 30 days.
How severe is CVE-2026-64042?
CVE-2026-64042 is rated High with a CVSS score of 8.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-64042?
Yes. A fix has been recorded for CVE-2026-64042. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-64042 affect?
CVE-2026-64042 affects Linux kernel (vfio/pci), KVM/QEMU VFIO device passthrough hosts, Virtual machines with VFIO guests. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-64042?
Apply kernel updates; restrict VFIO/DMABUF access and limit guest privileges.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
DMABUF export can expose unreserved PCI BARs, allowing unauthorized device memory access, data exposure and potential host privilege escalation/RCE from guests/local users.
Patch when possible
- affected>= 5d74781ebc86c5fa9e9d6934024c505412de9b52 and < 8443cd4497a4498c4b01058d76a92116244cb605
- affected>= 5d74781ebc86c5fa9e9d6934024c505412de9b52 and < 702809dabdecca807bdd50cfdcc1c980feb2ba62
- affected6.19
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.