KVM: nSVM: Raise #UD if unhandled VMMCALL isn't intercepted by L1
Summary
| CVE | CVE-2026-46076 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-05-27 14:17:28 UTC |
| Updated | 2026-05-30 11:17:20 UTC |
| Description | 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] |
Risk And Classification
Primary CVSS: v3.1 7.9 HIGH from 416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H
EPSS: 0.000180000 probability, percentile 0.049190000 (date 2026-05-29)
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | Secondary | 7.9 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H |
| 3.1 | CNA | DECLARED | 7.9 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H |
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
ChangedConfidentiality
LowIntegrity
LowAvailability
HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 3f4a812edf5cb0a50e65fbdfafdb3e688da18f16 924d721fae95687acedbaf624a094ed0e8b67104 git | Not specified |
| CNA | Linux | Linux | affected 3f4a812edf5cb0a50e65fbdfafdb3e688da18f16 009c0f726abeaa67aad1d96b883bdce01d405ce2 git | Not specified |
| CNA | Linux | Linux | affected 3f4a812edf5cb0a50e65fbdfafdb3e688da18f16 5fb4a5f361565f5b629d8a8fe5288ce8463c5727 git | Not specified |
| CNA | Linux | Linux | affected 3f4a812edf5cb0a50e65fbdfafdb3e688da18f16 c36991c6f8d2ab56ee67aff04e3c357f45cfc76c git | Not specified |
| CNA | Linux | Linux | affected 6.2 | Not specified |
| CNA | Linux | Linux | unaffected 6.2 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.86 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.27 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.0.4 7.0.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1-rc1 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/924d721fae95687acedbaf624a094ed0e8b67104 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/5fb4a5f361565f5b629d8a8fe5288ce8463c5727 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/009c0f726abeaa67aad1d96b883bdce01d405ce2 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/c36991c6f8d2ab56ee67aff04e3c357f45cfc76c | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.