{"id":"CVE-2026-46076","summary":"KVM: nSVM: Raise #UD if unhandled VMMCALL isn't intercepted by L1","details":"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]","modified":"2026-06-26T11:56:32.556450760Z","published":"2026-05-27T12:58:09.169Z","related":["openSUSE-SU-2026:10954-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46076.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/009c0f726abeaa67aad1d96b883bdce01d405ce2"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5fb4a5f361565f5b629d8a8fe5288ce8463c5727"},{"type":"WEB","url":"https://git.kernel.org/stable/c/924d721fae95687acedbaf624a094ed0e8b67104"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c36991c6f8d2ab56ee67aff04e3c357f45cfc76c"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46076.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-46076"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"3f4a812edf5cb0a50e65fbdfafdb3e688da18f16"},{"fixed":"924d721fae95687acedbaf624a094ed0e8b67104"},{"fixed":"009c0f726abeaa67aad1d96b883bdce01d405ce2"},{"fixed":"5fb4a5f361565f5b629d8a8fe5288ce8463c5727"},{"fixed":"c36991c6f8d2ab56ee67aff04e3c357f45cfc76c"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-46076.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.12.86"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.27"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-46076.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H"}]}