CVE-2026-31593 - Vulnerability Details

Vendors	Products
Linux Subscribe	Linux Kernel Subscribe

Link	Providers
https://git.kernel.org/stable/c/692fdf05e55fa03960a1278afdc2478c12daea13
https://git.kernel.org/stable/c/6ef109e01e1d35199e1a97ea68bdfd3cf3fbf9ab
https://git.kernel.org/stable/c/8f85a4885eee8cb495961ffa371a91828afb9445
https://git.kernel.org/stable/c/c9609847ae65ca36233077c2b6cb2bc0fb37c77a

Type	Values Removed	Values Added
Description		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().
Title		KVM: SEV: Reject attempts to sync VMSA of an already-launched/encrypted vCPU
First Time appeared		Linux Linux linux Kernel
CPEs		cpe:2.3:o:linux:linux_kernel::::::::
Vendors & Products		Linux Linux linux Kernel
References		https://git.kernel.org/stable/c/692fdf05e55fa03960a1278afdc2478c12daea13 https://git.kernel.org/stable/c/6ef109e01e1d35199e1a97ea68bdfd3cf3fbf9ab https://git.kernel.org/stable/c/8f85a4885eee8cb495961ffa371a91828afb9445 https://git.kernel.org/stable/c/c9609847ae65ca36233077c2b6cb2bc0fb37c77a

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-31593", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-03-09T15:48:24.121Z", "datePublished": "2026-04-24T14:42:19.567Z", "dateUpdated": "2026-04-24T14:42:19.567Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-04-24T14:42:19.567Z"}, "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 <TASK>\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 </TASK>\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()."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/x86/kvm/svm/sev.c"], "versions": [{"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "c9609847ae65ca36233077c2b6cb2bc0fb37c77a", "status": "affected", "versionType": "git"}, {"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "692fdf05e55fa03960a1278afdc2478c12daea13", "status": "affected", "versionType": "git"}, {"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "6ef109e01e1d35199e1a97ea68bdfd3cf3fbf9ab", "status": "affected", "versionType": "git"}, {"version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2", "lessThan": "8f85a4885eee8cb495961ffa371a91828afb9445", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/x86/kvm/svm/sev.c"], "versions": [{"version": "6.12.83", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.24", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.19.14", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0.1", "lessThanOrEqual": "7.0.*", "status": "unaffected", "versionType": "semver"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionEndExcluding": "6.12.83"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionEndExcluding": "6.18.24"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionEndExcluding": "6.19.14"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionEndExcluding": "7.0.1"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/c9609847ae65ca36233077c2b6cb2bc0fb37c77a"}, {"url": "https://git.kernel.org/stable/c/692fdf05e55fa03960a1278afdc2478c12daea13"}, {"url": "https://git.kernel.org/stable/c/6ef109e01e1d35199e1a97ea68bdfd3cf3fbf9ab"}, {"url": "https://git.kernel.org/stable/c/8f85a4885eee8cb495961ffa371a91828afb9445"}], "title": "KVM: SEV: Reject attempts to sync VMSA of an already-launched/encrypted vCPU", "x_generator": {"engine": "bippy-1.2.0"}}}}

{"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 <TASK>\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 </TASK>\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": "2026-04-24T17:51:40.810", "metrics": {}, "published": "2026-04-24T15:16:36.957", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/692fdf05e55fa03960a1278afdc2478c12daea13"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/6ef109e01e1d35199e1a97ea68bdfd3cf3fbf9ab"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/8f85a4885eee8cb495961ffa371a91828afb9445"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/c9609847ae65ca36233077c2b6cb2bc0fb37c77a"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Awaiting Analysis"}

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