FKIE_CVE-2026-64307
Vulnerability from fkie_nvd - Published: 2026-07-25 10:17 - Updated: 2026-09-04 13:08
Severity
Summary
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
References
Impacted products
| Vendor | Product | Version | |
|---|---|---|---|
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * |
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/crypto/ccp/sev-dev.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "345a6e869b33687e9268044bcaeeefd7c61da675",
"status": "affected",
"version": "1c3506ea8599a3ad1b9aae5cbd573134f8d18db7",
"versionType": "git"
},
{
"lessThan": "441ea32cf2755a0dc593557056b00b7caa0651f5",
"status": "affected",
"version": "ceac7fb89e8da465aec3ac3c20477f912f5c3a6c",
"versionType": "git"
},
{
"lessThan": "20f548cdac94860a164e5ebba4f7e4a01051cb06",
"status": "affected",
"version": "ceac7fb89e8da465aec3ac3c20477f912f5c3a6c",
"versionType": "git"
},
{
"lessThan": "08f0e65e784c4b20e6e620dd4f68d8636073a3d2",
"status": "affected",
"version": "ceac7fb89e8da465aec3ac3c20477f912f5c3a6c",
"versionType": "git"
},
{
"lessThan": "6.12.97",
"status": "affected",
"version": "6.12.75",
"versionType": "semver"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/crypto/ccp/sev-dev.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.16"
},
{
"lessThan": "6.16",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.97",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.39",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.4",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "ADEED594-2788-4BF2-B514-7C2CC3CA9228",
"versionEndExcluding": "6.12.97",
"versionStartIncluding": "6.12.75",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "FFBD7467-7FB0-4538-9CC0-98199E9EC402",
"versionEndExcluding": "6.18.39",
"versionStartIncluding": "6.16",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "6228DDD6-4557-4AA3-9F43-AB995D471E42",
"versionEndExcluding": "7.1.4",
"versionStartIncluding": "6.19",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: ccp - Do not initialize SNP for ioctl(SNP_CONFIG)\n\nSashiko notes:\n\n\u003e if SEV initialization fails and KVM is actively running normal VMs, could a\n\u003e userspace process trigger this code path via /dev/sev ioctls (e.g.,\n\u003e SEV_PDH_GEN) and zero out MSR_VM_HSAVE_PA globally? Would the next VMRUN\n\u003e execution for an active VM trigger a general protection fault and crash the\n\u003e host?\n\nRefuse to re-try initialization if SNP is not already initialized for\nSNP_CONFIG.\n\nThis is technically an ABI break: before if SNP initialization failed it\ncould be transparently retriggered by this ioctl, and if no VMs were\nrunning, everything worked fine. Hopefully this is enough of a corner case\nthat nobody will notice, but someone does, there are a few options:\n\n* do something like symbol_get() for kvm and refuse to initialize if KVM is\n loaded\n* check each cpu\u0027s HSAVE_PA for non-zero data before re-initializing\n* once initialization has failed, continue to refuse to initialize until\n the ccp module is unloaded"
}
],
"id": "CVE-2026-64307",
"lastModified": "2026-09-04T13:08:52.427",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 5.5,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 3.6,
"source": "nvd@nist.gov",
"type": "Primary"
}
]
},
"published": "2026-07-25T10:17:11.800",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/08f0e65e784c4b20e6e620dd4f68d8636073a3d2"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/20f548cdac94860a164e5ebba4f7e4a01051cb06"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/345a6e869b33687e9268044bcaeeefd7c61da675"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/441ea32cf2755a0dc593557056b00b7caa0651f5"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Analyzed",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "NVD-CWE-noinfo"
}
],
"source": "nvd@nist.gov",
"type": "Primary"
}
]
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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