{"api_version":"1","generated_at":"2026-06-03T09:09:13+00:00","cve":"CVE-2026-46014","urls":{"html":"https://cve.report/CVE-2026-46014","api":"https://cve.report/api/cve/CVE-2026-46014.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-46014","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-46014"},"summary":{"title":"KVM: SVM: Add missing save/restore handling of LBR MSRs","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SVM: Add missing save/restore handling of LBR MSRs\n\nMSR_IA32_DEBUGCTLMSR and LBR MSRs are currently not enumerated by\nKVM_GET_MSR_INDEX_LIST, and LBR MSRs cannot be set with KVM_SET_MSRS. So\nsave/restore is completely broken.\n\nFix it by adding the MSRs to msrs_to_save_base, and allowing writes to\nLBR MSRs from userspace only (as they are read-only MSRs) if LBR\nvirtualization is enabled.  Additionally, to correctly restore L1's LBRs\nwhile L2 is running, make sure the LBRs are copied from the captured\nVMCB01 save area in svm_copy_vmrun_state().\n\nNote, for VMX, this also fixes a flaw where MSR_IA32_DEBUGCTLMSR isn't\nreported as an MSR to save/restore.\n\nNote #2, over-reporting MSR_IA32_LASTxxx on Intel is ok, as KVM already\nhandles unsupported reads and writes thanks to commit b5e2fec0ebc3 (\"KVM:\nIgnore DEBUGCTL MSRs with no effect\") (kvm_do_msr_access() will morph the\nunsupported userspace write into a nop).\n\n[sean: guard with lbrv checks, massage changelog]","state":"PUBLISHED","assigner":"Linux","published_at":"2026-05-27 14:17:19","updated_at":"2026-05-27 14:48:03"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/2b922a42b531a82d7881add14a7698dcdc5e1f0a","name":"https://git.kernel.org/stable/c/2b922a42b531a82d7881add14a7698dcdc5e1f0a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/3700f0788da6acf73b2df56690f4b201aa4aefd2","name":"https://git.kernel.org/stable/c/3700f0788da6acf73b2df56690f4b201aa4aefd2","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/13a89ada5dcfc2539514c83ba5a2c61157f1ec6c","name":"https://git.kernel.org/stable/c/13a89ada5dcfc2539514c83ba5a2c61157f1ec6c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-46014","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-46014","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 24e09cbf480a72f9c952af4ca77b159503dca44b 2b922a42b531a82d7881add14a7698dcdc5e1f0a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 24e09cbf480a72f9c952af4ca77b159503dca44b 13a89ada5dcfc2539514c83ba5a2c61157f1ec6c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 24e09cbf480a72f9c952af4ca77b159503dca44b 3700f0788da6acf73b2df56690f4b201aa4aefd2 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2.6.26","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 2.6.26 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.27 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0.4 7.0.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"46014","cve":"CVE-2026-46014","epss":"0.000170000","percentile":"0.042650000","score_date":"2026-06-01","updated_at":"2026-06-02 00:05:21"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["arch/x86/kvm/svm/nested.c","arch/x86/kvm/svm/svm.c","arch/x86/kvm/x86.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"2b922a42b531a82d7881add14a7698dcdc5e1f0a","status":"affected","version":"24e09cbf480a72f9c952af4ca77b159503dca44b","versionType":"git"},{"lessThan":"13a89ada5dcfc2539514c83ba5a2c61157f1ec6c","status":"affected","version":"24e09cbf480a72f9c952af4ca77b159503dca44b","versionType":"git"},{"lessThan":"3700f0788da6acf73b2df56690f4b201aa4aefd2","status":"affected","version":"24e09cbf480a72f9c952af4ca77b159503dca44b","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["arch/x86/kvm/svm/nested.c","arch/x86/kvm/svm/svm.c","arch/x86/kvm/x86.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"2.6.26"},{"lessThan":"2.6.26","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.27","versionType":"semver"},{"lessThanOrEqual":"7.0.*","status":"unaffected","version":"7.0.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.1-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.27","versionStartIncluding":"2.6.26","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0.4","versionStartIncluding":"2.6.26","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1-rc1","versionStartIncluding":"2.6.26","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SVM: Add missing save/restore handling of LBR MSRs\n\nMSR_IA32_DEBUGCTLMSR and LBR MSRs are currently not enumerated by\nKVM_GET_MSR_INDEX_LIST, and LBR MSRs cannot be set with KVM_SET_MSRS. So\nsave/restore is completely broken.\n\nFix it by adding the MSRs to msrs_to_save_base, and allowing writes to\nLBR MSRs from userspace only (as they are read-only MSRs) if LBR\nvirtualization is enabled.  Additionally, to correctly restore L1's LBRs\nwhile L2 is running, make sure the LBRs are copied from the captured\nVMCB01 save area in svm_copy_vmrun_state().\n\nNote, for VMX, this also fixes a flaw where MSR_IA32_DEBUGCTLMSR isn't\nreported as an MSR to save/restore.\n\nNote #2, over-reporting MSR_IA32_LASTxxx on Intel is ok, as KVM already\nhandles unsupported reads and writes thanks to commit b5e2fec0ebc3 (\"KVM:\nIgnore DEBUGCTL MSRs with no effect\") (kvm_do_msr_access() will morph the\nunsupported userspace write into a nop).\n\n[sean: guard with lbrv checks, massage changelog]"}],"providerMetadata":{"dateUpdated":"2026-05-27T12:56:16.052Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/2b922a42b531a82d7881add14a7698dcdc5e1f0a"},{"url":"https://git.kernel.org/stable/c/13a89ada5dcfc2539514c83ba5a2c61157f1ec6c"},{"url":"https://git.kernel.org/stable/c/3700f0788da6acf73b2df56690f4b201aa4aefd2"}],"title":"KVM: SVM: Add missing save/restore handling of LBR MSRs","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-46014","datePublished":"2026-05-27T12:56:16.052Z","dateReserved":"2026-05-13T15:03:33.092Z","dateUpdated":"2026-05-27T12:56:16.052Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-27 14:17:19","lastModifiedDate":"2026-05-27 14:48:03","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"46014","Ordinal":"1","Title":"KVM: SVM: Add missing save/restore handling of LBR MSRs","CVE":"CVE-2026-46014","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"46014","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SVM: Add missing save/restore handling of LBR MSRs\n\nMSR_IA32_DEBUGCTLMSR and LBR MSRs are currently not enumerated by\nKVM_GET_MSR_INDEX_LIST, and LBR MSRs cannot be set with KVM_SET_MSRS. So\nsave/restore is completely broken.\n\nFix it by adding the MSRs to msrs_to_save_base, and allowing writes to\nLBR MSRs from userspace only (as they are read-only MSRs) if LBR\nvirtualization is enabled.  Additionally, to correctly restore L1's LBRs\nwhile L2 is running, make sure the LBRs are copied from the captured\nVMCB01 save area in svm_copy_vmrun_state().\n\nNote, for VMX, this also fixes a flaw where MSR_IA32_DEBUGCTLMSR isn't\nreported as an MSR to save/restore.\n\nNote #2, over-reporting MSR_IA32_LASTxxx on Intel is ok, as KVM already\nhandles unsupported reads and writes thanks to commit b5e2fec0ebc3 (\"KVM:\nIgnore DEBUGCTL MSRs with no effect\") (kvm_do_msr_access() will morph the\nunsupported userspace write into a nop).\n\n[sean: guard with lbrv checks, massage changelog]","Type":"Description","Title":"KVM: SVM: Add missing save/restore handling of LBR MSRs"}]}}}