{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2026-43315", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-43315", "idYear": 2026, "status": "PUBLISHED", "publishedAt": "2026-05-08T13:11:31.784Z", "updatedAt": "2026-05-11T22:22:10.929Z", "importedAt": "2026-10-24T01:58:14.884Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "KVM: nSVM: Remove a user-triggerable WARN on nested_svm_load_cr3() succeeding", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: nSVM: Remove a user-triggerable WARN on nested_svm_load_cr3() succeeding\n\nDrop the WARN in svm_set_nested_state() on nested_svm_load_cr3() failing\nas it is trivially easy to trigger from userspace by modifying CPUID after\nloading CR3. E.g. modifying the state restoration selftest like so:\n\n --- tools/testing/selftests/kvm/x86/state_test.c\n +++ tools/testing/selftests/kvm/x86/state_test.c\n @@ -280,7 +280,16 @@ int main(int argc, char *argv[])\n\n /* Restore state in a new VM. */\n vcpu = vm_recreate_with_one_vcpu(vm);\n - vcpu_load_state(vcpu, state);\n +\n + if (stage == 4) {\n + state->sregs.cr3 = BIT(44);\n + vcpu_load_state(vcpu, state);\n +\n + vcpu_set_cpuid_property(vcpu, X86_PROPERTY_MAX_PHY_ADDR, 36);\n + __vcpu_nested_state_set(vcpu, &state->nested);\n + } else {\n + vcpu_load_state(vcpu, state);\n + }\n\n /*\n * Restore XSAVE state in a dummy vCPU, first without doing\n\ngenerates:\n\n WARNING: CPU: 30 PID: 938 at arch/x86/kvm/svm/nested.c:1877 svm_set_nested_state+0x34a/0x360 [kvm_amd]\n Modules linked in: kvm_amd kvm irqbypass [last unloaded: kvm]\n CPU: 30 UID: 1000 PID: 938 Comm: state_test Tainted: G W 6.18.0-rc7-58e10b63777d-next-vm\n Tainted: [W]=WARN\n Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015\n RIP: 0010:svm_set_nested_state+0x34a/0x360 [kvm_amd]\n Call Trace:\n \n kvm_arch_vcpu_ioctl+0xf33/0x1700 [kvm]\n kvm_vcpu_ioctl+0x4e6/0x8f0 [kvm]\n __x64_sys_ioctl+0x8f/0xd0\n do_syscall_64+0x61/0xad0\n entry_SYSCALL_64_after_hwframe+0x4b/0x53\n\nSimply delete the WARN instead of trying to prevent userspace from shoving\n\"illegal\" state into CR3. For better or worse, KVM's ABI allows userspace\nto set CPUID after SREGS, and vice versa, and KVM is very permissive when\nit comes to guest CPUID. I.e. attempting to enforce the virtual CPU model\nwhen setting CPUID could break userspace. Given that the WARN doesn't\nprovide any meaningful protection for KVM or benefit for userspace, simply\ndrop it even though the odds of breaking userspace are minuscule.\n\nOpportunistically delete a spurious newline.", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "b222b0b88162bdef4eceb12a79d5edbbdb23dbfd", "status": "affected", "versionType": "git", "lessThan": "155ec243ef726f4bc49536fa0bfb565dc011ab17" }, { "version": "b222b0b88162bdef4eceb12a79d5edbbdb23dbfd", "status": "affected", "versionType": "git", "lessThan": "580ea57840864d40e019bc13fd26afdc8d510a2f" }, { "version": "b222b0b88162bdef4eceb12a79d5edbbdb23dbfd", "status": "affected", "versionType": "git", "lessThan": "deb8f6dfd31d94b18dbeeaa8c01fbec5fc70fd2b" }, { "version": "b222b0b88162bdef4eceb12a79d5edbbdb23dbfd", "status": "affected", "versionType": "git", "lessThan": "ce904c8a5bbe697eae0f7e34b07095bd7a6dee19" }, { "version": "b222b0b88162bdef4eceb12a79d5edbbdb23dbfd", "status": "affected", "versionType": "git", "lessThan": "969e5e13ff5c18603f21d1f9f64ec9194e141ac0" }, { "version": "b222b0b88162bdef4eceb12a79d5edbbdb23dbfd", "status": "affected", "versionType": "git", "lessThan": "ebb2ab4f1c87d6b52776292cf7dc16aea48e95f8" }, { "version": "b222b0b88162bdef4eceb12a79d5edbbdb23dbfd", "status": "affected", "versionType": "git", "lessThan": "fc3ba56385d03501eb582e4b86691ba378e556f9" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "5.14", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "5.14" }, { "version": "5.15.202", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.15.*" }, { "version": "6.1.165", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.6.128", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.12.75", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.18.16", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.18.*" }, { "version": "6.19.6", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.19.*" }, { "version": "7.0", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }