FKIE_CVE-2026-31593
Vulnerability from fkie_nvd - Published: 2026-04-24 15:16 - Updated: 2026-06-17 10:34
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
KVM: SEV: Reject attempts to sync VMSA of an already-launched/encrypted vCPU
Reject synchronizing vCPU state to its associated VMSA if the vCPU has
already been launched, i.e. if the VMSA has already been encrypted. On a
host with SNP enabled, accessing guest-private memory generates an RMP #PF
and panics the host.
BUG: unable to handle page fault for address: ff1276cbfdf36000
#PF: supervisor write access in kernel mode
#PF: error_code(0x80000003) - RMP violation
PGD 5a31801067 P4D 5a31802067 PUD 40ccfb5063 PMD 40e5954063 PTE 80000040fdf36163
SEV-SNP: PFN 0x40fdf36, RMP entry: [0x6010fffffffff001 - 0x000000000000001f]
Oops: Oops: 0003 [#1] SMP NOPTI
CPU: 33 UID: 0 PID: 996180 Comm: qemu-system-x86 Tainted: G OE
Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE
Hardware name: Dell Inc. PowerEdge R7625/0H1TJT, BIOS 1.5.8 07/21/2023
RIP: 0010:sev_es_sync_vmsa+0x54/0x4c0 [kvm_amd]
Call Trace:
<TASK>
snp_launch_update_vmsa+0x19d/0x290 [kvm_amd]
snp_launch_finish+0xb6/0x380 [kvm_amd]
sev_mem_enc_ioctl+0x14e/0x720 [kvm_amd]
kvm_arch_vm_ioctl+0x837/0xcf0 [kvm]
kvm_vm_ioctl+0x3fd/0xcc0 [kvm]
__x64_sys_ioctl+0xa3/0x100
x64_sys_call+0xfe0/0x2350
do_syscall_64+0x81/0x10f0
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7ffff673287d
</TASK>
Note, the KVM flaw has been present since commit ad73109ae7ec ("KVM: SVM:
Provide support to launch and run an SEV-ES guest"), but has only been
actively dangerous for the host since SNP support was added. With SEV-ES,
KVM would "just" clobber guest state, which is totally fine from a host
kernel perspective since userspace can clobber guest state any time before
sev_launch_update_vmsa().
References
Impacted products
| Vendor | Product | Version | |
|---|---|---|---|
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | * |
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"arch/x86/kvm/svm/sev.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "c9609847ae65ca36233077c2b6cb2bc0fb37c77a",
"status": "affected",
"version": "ad27ce155566f2b4400fa865859834592bd18777",
"versionType": "git"
},
{
"lessThan": "692fdf05e55fa03960a1278afdc2478c12daea13",
"status": "affected",
"version": "ad27ce155566f2b4400fa865859834592bd18777",
"versionType": "git"
},
{
"lessThan": "6ef109e01e1d35199e1a97ea68bdfd3cf3fbf9ab",
"status": "affected",
"version": "ad27ce155566f2b4400fa865859834592bd18777",
"versionType": "git"
},
{
"lessThan": "8f85a4885eee8cb495961ffa371a91828afb9445",
"status": "affected",
"version": "ad27ce155566f2b4400fa865859834592bd18777",
"versionType": "git"
},
{
"lessThan": "9b9f7962e3e879d12da2bf47e02a24ec51690e3d",
"status": "affected",
"version": "ad27ce155566f2b4400fa865859834592bd18777",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"arch/x86/kvm/svm/sev.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.11"
},
{
"lessThan": "6.11",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.83",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.24",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.19.*",
"status": "unaffected",
"version": "6.19.14",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.0.*",
"status": "unaffected",
"version": "7.0.1",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "ABF3F6D0-27D6-43E7-BF38-1B493B03EC1F",
"versionEndExcluding": "6.12.83",
"versionStartIncluding": "6.11",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "8126B8B8-6D0B-4443-86C1-672AEE893555",
"versionEndExcluding": "6.18.24",
"versionStartIncluding": "6.13",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "D6A8A074-BBF4-4803-ABED-519A839435BB",
"versionEndExcluding": "6.19.14",
"versionStartIncluding": "6.19",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "9B5888AB-7403-4335-89E4-21CC0B48366A",
"versionEndExcluding": "7.0.1",
"versionStartIncluding": "7.0",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SEV: Reject attempts to sync VMSA of an already-launched/encrypted vCPU\n\nReject synchronizing vCPU state to its associated VMSA if the vCPU has\nalready been launched, i.e. if the VMSA has already been encrypted. On a\nhost with SNP enabled, accessing guest-private memory generates an RMP #PF\nand panics the host.\n\n BUG: unable to handle page fault for address: ff1276cbfdf36000\n #PF: supervisor write access in kernel mode\n #PF: error_code(0x80000003) - RMP violation\n PGD 5a31801067 P4D 5a31802067 PUD 40ccfb5063 PMD 40e5954063 PTE 80000040fdf36163\n SEV-SNP: PFN 0x40fdf36, RMP entry: [0x6010fffffffff001 - 0x000000000000001f]\n Oops: Oops: 0003 [#1] SMP NOPTI\n CPU: 33 UID: 0 PID: 996180 Comm: qemu-system-x86 Tainted: G OE\n Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE\n Hardware name: Dell Inc. PowerEdge R7625/0H1TJT, BIOS 1.5.8 07/21/2023\n RIP: 0010:sev_es_sync_vmsa+0x54/0x4c0 [kvm_amd]\n Call Trace:\n \u003cTASK\u003e\n snp_launch_update_vmsa+0x19d/0x290 [kvm_amd]\n snp_launch_finish+0xb6/0x380 [kvm_amd]\n sev_mem_enc_ioctl+0x14e/0x720 [kvm_amd]\n kvm_arch_vm_ioctl+0x837/0xcf0 [kvm]\n kvm_vm_ioctl+0x3fd/0xcc0 [kvm]\n __x64_sys_ioctl+0xa3/0x100\n x64_sys_call+0xfe0/0x2350\n do_syscall_64+0x81/0x10f0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n RIP: 0033:0x7ffff673287d\n \u003c/TASK\u003e\n\nNote, the KVM flaw has been present since commit ad73109ae7ec (\"KVM: SVM:\nProvide support to launch and run an SEV-ES guest\"), but has only been\nactively dangerous for the host since SNP support was added. With SEV-ES,\nKVM would \"just\" clobber guest state, which is totally fine from a host\nkernel perspective since userspace can clobber guest state any time before\nsev_launch_update_vmsa()."
}
],
"id": "CVE-2026-31593",
"lastModified": "2026-06-17T10:34:02.900",
"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": "2026-04-24T15:16:36.957",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/692fdf05e55fa03960a1278afdc2478c12daea13"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/6ef109e01e1d35199e1a97ea68bdfd3cf3fbf9ab"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/8f85a4885eee8cb495961ffa371a91828afb9445"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/9b9f7962e3e879d12da2bf47e02a24ec51690e3d"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/c9609847ae65ca36233077c2b6cb2bc0fb37c77a"
}
],
"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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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
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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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