CVE-2026-46076 (GCVE-0-2026-46076)

Vulnerability from cvelistv5 – Published: 2026-05-27 12:58 – Updated: 2026-06-14 17:52
VLAI
Title
KVM: nSVM: Raise #UD if unhandled VMMCALL isn't intercepted by L1
Summary
In the Linux kernel, the following vulnerability has been resolved: KVM: nSVM: Raise #UD if unhandled VMMCALL isn't intercepted by L1 Explicitly synthesize a #UD for VMMCALL if L2 is active, L1 does NOT want to intercept VMMCALL, nested_svm_l2_tlb_flush_enabled() is true, and the hypercall is something other than one of the supported Hyper-V hypercalls. When all of the above conditions are met, KVM will intercept VMMCALL but never forward it to L1, i.e. will let L2 make hypercalls as if it were L1. The TLFS says a whole lot of nothing about this scenario, so go with the architectural behavior, which says that VMMCALL #UDs if it's not intercepted. Opportunistically do a 2-for-1 stub trade by stub-ifying the new API instead of the helpers it uses. The last remaining "single" stub will soon be dropped as well. [sean: rewrite changelog and comment, tag for stable, remove defunct stubs]
Severity
7.9 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 3f4a812edf5cb0a50e65fbdfafdb3e688da18f16 , < 924d721fae95687acedbaf624a094ed0e8b67104 (git)
Affected: 3f4a812edf5cb0a50e65fbdfafdb3e688da18f16 , < 009c0f726abeaa67aad1d96b883bdce01d405ce2 (git)
Affected: 3f4a812edf5cb0a50e65fbdfafdb3e688da18f16 , < 5fb4a5f361565f5b629d8a8fe5288ce8463c5727 (git)
Affected: 3f4a812edf5cb0a50e65fbdfafdb3e688da18f16 , < c36991c6f8d2ab56ee67aff04e3c357f45cfc76c (git)
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Linux Linux Affected: 6.2
Unaffected: 0 , < 6.2 (semver)
Unaffected: 6.12.86 , ≤ 6.12.* (semver)
Unaffected: 6.18.27 , ≤ 6.18.* (semver)
Unaffected: 7.0.4 , ≤ 7.0.* (semver)
Unaffected: 7.1 , ≤ * (original_commit_for_fix)
Create a notification for this product.
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{
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    "dateReserved": "2026-05-13T15:03:33.096Z",
    "dateUpdated": "2026-06-14T17:52:33.456Z",
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      "product_status:known_affected": "3",
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      "status": "final",
      "title": "KVM: nSVM: Raise #UD if unhandled VMMCALL isn\u0027t intercepted by L1",
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The last remaining \\\"single\\\" stub will\\nsoon be dropped as well.\\n\\n[sean: rewrite changelog and comment, tag for stable, remove defunct stubs]\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"arch/x86/kvm/hyperv.h\",\"arch/x86/kvm/svm/hyperv.h\",\"arch/x86/kvm/svm/nested.c\",\"arch/x86/kvm/svm/svm.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"3f4a812edf5cb0a50e65fbdfafdb3e688da18f16\",\"lessThan\":\"924d721fae95687acedbaf624a094ed0e8b67104\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"3f4a812edf5cb0a50e65fbdfafdb3e688da18f16\",\"lessThan\":\"009c0f726abeaa67aad1d96b883bdce01d405ce2\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"3f4a812edf5cb0a50e65fbdfafdb3e688da18f16\",\"lessThan\":\"5fb4a5f361565f5b629d8a8fe5288ce8463c5727\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"3f4a812edf5cb0a50e65fbdfafdb3e688da18f16\",\"lessThan\":\"c36991c6f8d2ab56ee67aff04e3c357f45cfc76c\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"arch/x86/kvm/hyperv.h\",\"arch/x86/kvm/svm/hyperv.h\",\"arch/x86/kvm/svm/nested.c\",\"arch/x86/kvm/svm/svm.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6.2\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"6.2\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.86\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.27\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.0.4\",\"lessThanOrEqual\":\"7.0.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H\",\"baseScore\":7.9,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"CHANGED\",\"confidentialityImpact\":\"LOW\",\"integrityImpact\":\"LOW\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":2.0,\"impactScore\":5.3}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"NVD-CWE-noinfo\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.2\",\"versionEndExcluding\":\"6.12.86\",\"matchCriteriaId\":\"B33E0975-006A-45BB-AD35-19D8D80F6676\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.13\",\"versionEndExcluding\":\"6.18.27\",\"matchCriteriaId\":\"A10AC84F-C058-47D5-85B4-E6E51A613B74\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"6.19\",\"versionEndExcluding\":\"7.0.4\",\"matchCriteriaId\":\"CDB78D6D-22C3-4154-B0D0-94AF1CE5C2E3\"}]}]}],\"references\":[{\"url\":\"https://git.kernel.org/stable/c/009c0f726abeaa67aad1d96b883bdce01d405ce2\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/5fb4a5f361565f5b629d8a8fe5288ce8463c5727\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/924d721fae95687acedbaf624a094ed0e8b67104\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]},{\"url\":\"https://git.kernel.org/stable/c/c36991c6f8d2ab56ee67aff04e3c357f45cfc76c\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"tags\":[\"Patch\"]}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-06-28T07:40:46+00:00",
      "cve": "CVE-2026-46076",
      "id": "CVE-2026-46076",
      "initial_release_date": "2026-05-27T00:00:00+00:00",
      "product_status:known_affected": "184",
      "product_status:known_not_affected": "90",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: KVM: nSVM: Raise #UD if unhandled VMMCALL isn\u0027t intercepted by L1",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-46076.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "important",
      "current_release_date": "2026-07-21T23:55:29Z",
      "cve": "CVE-2026-46076",
      "id": "CVE-2026-46076",
      "initial_release_date": "2026-05-28T03:53:06Z",
      "product_status:first_fixed": "68",
      "product_status:known_affected": "17",
      "product_status:known_not_affected": "179",
      "product_status:recommended": "182",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-46076",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-46076.json",
      "version": "12"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.