{"id":"CVE-2026-46076","revision":"4d3a0aefb11e4c8f8f4cea7b4e85d747","records":[{"revision":"4d3a0aefb11e4c8f8f4cea7b4e85d747","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-46076","aliases":[],"title":"KVM: nSVM: Raise #UD if unhandled VMMCALL isn't intercepted by L1","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: nSVM: Raise #UD if unhandled VMMCALL isn't intercepted by L1\n\nExplicitly synthesize a #UD for VMMCALL if L2 is active, L1 does NOT want\nto intercept VMMCALL, nested_svm_l2_tlb_flush_enabled() is true, and the\nhypercall is something other than one of the supported Hyper-V hypercalls.\nWhen all of the above conditions are met, KVM will intercept VMMCALL but\nnever forward it to L1, i.e. will let L2 make hypercalls as if it were L1.\n\nThe TLFS says a whole lot of nothing about this scenario, so go with the\narchitectural behavior, which says that VMMCALL #UDs if it's not\nintercepted.\n\nOpportunistically do a 2-for-1 stub trade by stub-ifying the new API\ninstead of the helpers it uses.  The last remaining \"single\" stub will\nsoon be dropped as well.\n\n[sean: rewrite changelog and comment, tag for stable, remove defunct stubs]","state":0,"publishedAt":"2026-05-27T12:58:09.169+00:00","modifiedAt":"2026-10-21T12:41:18.394+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"arch/x86/kvm/hyperv.h\",\n                        \"arch/x86/kvm/svm/hyperv.h\",\n                        \"arch/x86/kvm/svm/nested.c\",\n                        \"arch/x86/kvm/svm/svm.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"3f4a812edf5cb0a50e65fbdfafdb3e688da18f16\",\n                            \"lessThan\": \"fcef67506c0234935cb0fb026740a637edb58d7c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3f4a812edf5cb0a50e65fbdfafdb3e688da18f16\",\n                            \"lessThan\": \"924d721fae95687acedbaf624a094ed0e8b67104\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3f4a812edf5cb0a50e65fbdfafdb3e688da18f16\",\n                            \"lessThan\": \"009c0f726abeaa67aad1d96b883bdce01d405ce2\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3f4a812edf5cb0a50e65fbdfafdb3e688da18f16\",\n                            \"lessThan\": \"5fb4a5f361565f5b629d8a8fe5288ce8463c5727\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3f4a812edf5cb0a50e65fbdfafdb3e688da18f16\",\n                            \"lessThan\": \"c36991c6f8d2ab56ee67aff04e3c357f45cfc76c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"arch/x86/kvm/hyperv.h\",\n                        \"arch/x86/kvm/svm/hyperv.h\",\n                        \"arch/x86/kvm/svm/nested.c\",\n                        \"arch/x86/kvm/svm/svm.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.2\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.2\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.160\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.86\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.27\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.0.4\",\n                            \"lessThanOrEqual\": \"7.0.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H","score":7.9,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/fcef67506c0234935cb0fb026740a637edb58d7c","https://git.kernel.org/stable/c/924d721fae95687acedbaf624a094ed0e8b67104","https://git.kernel.org/stable/c/009c0f726abeaa67aad1d96b883bdce01d405ce2","https://git.kernel.org/stable/c/5fb4a5f361565f5b629d8a8fe5288ce8463c5727","https://git.kernel.org/stable/c/c36991c6f8d2ab56ee67aff04e3c357f45cfc76c"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-46076","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-46076","identifiers":["CVE-2026-46076"]},"retained":false,"historicalAffected":[]}],"coverage":[]}