{"api_version":"1","generated_at":"2026-05-13T19:31:03+00:00","cve":"CVE-2026-43483","urls":{"html":"https://cve.report/CVE-2026-43483","api":"https://cve.report/api/cve/CVE-2026-43483.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-43483","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-43483"},"summary":{"title":"KVM: SVM: Set/clear CR8 write interception when AVIC is (de)activated","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SVM: Set/clear CR8 write interception when AVIC is (de)activated\n\nExplicitly set/clear CR8 write interception when AVIC is (de)activated to\nfix a bug where KVM leaves the interception enabled after AVIC is\nactivated.  E.g. if KVM emulates INIT=>WFS while AVIC is deactivated, CR8\nwill remain intercepted in perpetuity.\n\nOn its own, the dangling CR8 intercept is \"just\" a performance issue, but\ncombined with the TPR sync bug fixed by commit d02e48830e3f (\"KVM: SVM:\nSync TPR from LAPIC into VMCB::V_TPR even if AVIC is active\"), the danging\nintercept is fatal to Windows guests as the TPR seen by hardware gets\nwildly out of sync with reality.\n\nNote, VMX isn't affected by the bug as TPR_THRESHOLD is explicitly ignored\nwhen Virtual Interrupt Delivery is enabled, i.e. when APICv is active in\nKVM's world.  I.e. there's no need to trigger update_cr8_intercept(), this\nis firmly an SVM implementation flaw/detail.\n\nWARN if KVM gets a CR8 write #VMEXIT while AVIC is active, as KVM should\nnever enter the guest with AVIC enabled and CR8 writes intercepted.\n\n[Squash fix to avic_deactivate_vmcb. - Paolo]","state":"PUBLISHED","assigner":"Linux","published_at":"2026-05-13 16:16:51","updated_at":"2026-05-13 16:16:51"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/a4123fe5d9122eef9852e4921f7cc463420f30d4","name":"https://git.kernel.org/stable/c/a4123fe5d9122eef9852e4921f7cc463420f30d4","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/ba3bca40f9f25c053f69413e5f4a41dd0fd762bf","name":"https://git.kernel.org/stable/c/ba3bca40f9f25c053f69413e5f4a41dd0fd762bf","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/816fa1dfae4532e851b1fe6b2434c753ecbd86c7","name":"https://git.kernel.org/stable/c/816fa1dfae4532e851b1fe6b2434c753ecbd86c7","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/87d0f901a9bd8ae6be57249c737f20ac0cace93d","name":"https://git.kernel.org/stable/c/87d0f901a9bd8ae6be57249c737f20ac0cace93d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/737410b32bd615b321da4fbeda490351b9af5e8b","name":"https://git.kernel.org/stable/c/737410b32bd615b321da4fbeda490351b9af5e8b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/01651e7751edbbc0fb4598f8367a3dabcfc8c182","name":"https://git.kernel.org/stable/c/01651e7751edbbc0fb4598f8367a3dabcfc8c182","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-43483","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43483","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3bbf3565f48ce3999b5a12cde946f81bd4475312 a4123fe5d9122eef9852e4921f7cc463420f30d4 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3bbf3565f48ce3999b5a12cde946f81bd4475312 816fa1dfae4532e851b1fe6b2434c753ecbd86c7 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3bbf3565f48ce3999b5a12cde946f81bd4475312 01651e7751edbbc0fb4598f8367a3dabcfc8c182 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3bbf3565f48ce3999b5a12cde946f81bd4475312 ba3bca40f9f25c053f69413e5f4a41dd0fd762bf git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3bbf3565f48ce3999b5a12cde946f81bd4475312 737410b32bd615b321da4fbeda490351b9af5e8b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 3bbf3565f48ce3999b5a12cde946f81bd4475312 87d0f901a9bd8ae6be57249c737f20ac0cace93d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4.7","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 4.7 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.167 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.130 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.78 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.19 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.19.9 6.19.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["arch/x86/kvm/svm/avic.c","arch/x86/kvm/svm/svm.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"a4123fe5d9122eef9852e4921f7cc463420f30d4","status":"affected","version":"3bbf3565f48ce3999b5a12cde946f81bd4475312","versionType":"git"},{"lessThan":"816fa1dfae4532e851b1fe6b2434c753ecbd86c7","status":"affected","version":"3bbf3565f48ce3999b5a12cde946f81bd4475312","versionType":"git"},{"lessThan":"01651e7751edbbc0fb4598f8367a3dabcfc8c182","status":"affected","version":"3bbf3565f48ce3999b5a12cde946f81bd4475312","versionType":"git"},{"lessThan":"ba3bca40f9f25c053f69413e5f4a41dd0fd762bf","status":"affected","version":"3bbf3565f48ce3999b5a12cde946f81bd4475312","versionType":"git"},{"lessThan":"737410b32bd615b321da4fbeda490351b9af5e8b","status":"affected","version":"3bbf3565f48ce3999b5a12cde946f81bd4475312","versionType":"git"},{"lessThan":"87d0f901a9bd8ae6be57249c737f20ac0cace93d","status":"affected","version":"3bbf3565f48ce3999b5a12cde946f81bd4475312","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["arch/x86/kvm/svm/avic.c","arch/x86/kvm/svm/svm.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"4.7"},{"lessThan":"4.7","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.167","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.130","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.78","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.19","versionType":"semver"},{"lessThanOrEqual":"6.19.*","status":"unaffected","version":"6.19.9","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.0","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.167","versionStartIncluding":"4.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.130","versionStartIncluding":"4.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.78","versionStartIncluding":"4.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.19","versionStartIncluding":"4.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.19.9","versionStartIncluding":"4.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0","versionStartIncluding":"4.7","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SVM: Set/clear CR8 write interception when AVIC is (de)activated\n\nExplicitly set/clear CR8 write interception when AVIC is (de)activated to\nfix a bug where KVM leaves the interception enabled after AVIC is\nactivated.  E.g. if KVM emulates INIT=>WFS while AVIC is deactivated, CR8\nwill remain intercepted in perpetuity.\n\nOn its own, the dangling CR8 intercept is \"just\" a performance issue, but\ncombined with the TPR sync bug fixed by commit d02e48830e3f (\"KVM: SVM:\nSync TPR from LAPIC into VMCB::V_TPR even if AVIC is active\"), the danging\nintercept is fatal to Windows guests as the TPR seen by hardware gets\nwildly out of sync with reality.\n\nNote, VMX isn't affected by the bug as TPR_THRESHOLD is explicitly ignored\nwhen Virtual Interrupt Delivery is enabled, i.e. when APICv is active in\nKVM's world.  I.e. there's no need to trigger update_cr8_intercept(), this\nis firmly an SVM implementation flaw/detail.\n\nWARN if KVM gets a CR8 write #VMEXIT while AVIC is active, as KVM should\nnever enter the guest with AVIC enabled and CR8 writes intercepted.\n\n[Squash fix to avic_deactivate_vmcb. - Paolo]"}],"providerMetadata":{"dateUpdated":"2026-05-13T15:08:30.319Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/a4123fe5d9122eef9852e4921f7cc463420f30d4"},{"url":"https://git.kernel.org/stable/c/816fa1dfae4532e851b1fe6b2434c753ecbd86c7"},{"url":"https://git.kernel.org/stable/c/01651e7751edbbc0fb4598f8367a3dabcfc8c182"},{"url":"https://git.kernel.org/stable/c/ba3bca40f9f25c053f69413e5f4a41dd0fd762bf"},{"url":"https://git.kernel.org/stable/c/737410b32bd615b321da4fbeda490351b9af5e8b"},{"url":"https://git.kernel.org/stable/c/87d0f901a9bd8ae6be57249c737f20ac0cace93d"}],"title":"KVM: SVM: Set/clear CR8 write interception when AVIC is (de)activated","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-43483","datePublished":"2026-05-13T15:08:30.319Z","dateReserved":"2026-05-01T14:12:56.012Z","dateUpdated":"2026-05-13T15:08:30.319Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-13 16:16:51","lastModifiedDate":"2026-05-13 16:16:51","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"43483","Ordinal":"1","Title":"KVM: SVM: Set/clear CR8 write interception when AVIC is (de)acti","CVE":"CVE-2026-43483","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"43483","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SVM: Set/clear CR8 write interception when AVIC is (de)activated\n\nExplicitly set/clear CR8 write interception when AVIC is (de)activated to\nfix a bug where KVM leaves the interception enabled after AVIC is\nactivated.  E.g. if KVM emulates INIT=>WFS while AVIC is deactivated, CR8\nwill remain intercepted in perpetuity.\n\nOn its own, the dangling CR8 intercept is \"just\" a performance issue, but\ncombined with the TPR sync bug fixed by commit d02e48830e3f (\"KVM: SVM:\nSync TPR from LAPIC into VMCB::V_TPR even if AVIC is active\"), the danging\nintercept is fatal to Windows guests as the TPR seen by hardware gets\nwildly out of sync with reality.\n\nNote, VMX isn't affected by the bug as TPR_THRESHOLD is explicitly ignored\nwhen Virtual Interrupt Delivery is enabled, i.e. when APICv is active in\nKVM's world.  I.e. there's no need to trigger update_cr8_intercept(), this\nis firmly an SVM implementation flaw/detail.\n\nWARN if KVM gets a CR8 write #VMEXIT while AVIC is active, as KVM should\nnever enter the guest with AVIC enabled and CR8 writes intercepted.\n\n[Squash fix to avic_deactivate_vmcb. - Paolo]","Type":"Description","Title":"KVM: SVM: Set/clear CR8 write interception when AVIC is (de)acti"}]}}}