Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
CVE-2026-64307
Linux Linux — crypto: ccp - Do not initialize SNP for ioctl(SNP_CONFIG)
AV AC PR UI S C I A CVSS EPSS %ile KEV
L L L N U N N H 5.5 .0017 5.6 —
AFFECTED
Product Versions Fixed
Linux 1c3506ea8599a3ad1b9aae5cbd573134f8d18db7 – —
Linux 6.16 – 6.12.97
TIMELINE
Jul 19 Reserved by Linux
Jul 25 Published (CNA: Linux)
Sep 4 ENRICHED — CVE-2026-64307 (Linux). Received CVSS 5.5 and CPE data from NVD.
Description
In the Linux kernel, the following vulnerability has been resolved:
crypto: ccp - Do not initialize SNP for ioctl(SNP_CONFIG)
Sashiko notes:
> if SEV initialization fails and KVM is actively running normal VMs, could a
> userspace process trigger this code path via /dev/sev ioctls (e.g.,
> SEV_PDH_GEN) and zero out MSR_VM_HSAVE_PA globally? Would the next VMRUN
> execution for an active VM trigger a general protection fault and crash the
> host?
Refuse to re-try initialization if SNP is not already initialized for
SNP_CONFIG.
This is technically an ABI break: before if SNP initialization failed it
could be transparently retriggered by this ioctl, and if no VMs were
running, everything worked fine. Hopefully this is enough of a corner case
that nobody will notice, but someone does, there are a few options:
* do something like symbol_get() for kvm and refuse to initialize if KVM is
loaded
* check each cpu's HSAVE_PA for non-zero data before re-initializing
* once initialization has failed, continue to refuse to initialize until
the ccp module is unloaded
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
| July 19, 2026 | Reserved | Reserved by Linux |
| July 25, 2026 | Published | Published (CNA: Linux) |
| September 4, 2026 | ENRICHED | ENRICHED — CVE-2026-64307 (Linux). Received CVSS 5.5 and CPE data from NVD. |
Affected
Affected products and packages — 2 rows
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
| Linux | Linux | — | 1c3506ea8599a3ad1b9aae5cbd573134f8d18db7 | — |
| Linux | Linux | — | 6.16 | 6.12.97 |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-64307 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.