CVE-2026-89930KVM: nVMX: Service local TLB flushes on failed nested VM-Enter
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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In the Linux kernel, the following vulnerability has been resolved: KVM: nVMX: Service local TLB flushes on failed nested VM-Enter KVM services local TLB flushes on "full" nested VM-Exits (through __nested_vmx_vmexit()), but not if a nested VM-Enter fails (e.g. due to failed VMCS checks in nested_vmx_enter_non_root_mode()). However, it is possible that KVM had queued TLB flushes that need to be performed, even if the nested VM-Enter was not successful. For example, if VPID is disabled for L2 (via nested_vmx_transition_tlb_flush(), or if via the MSR load lists, as the SDM says: If any MSR is being loaded in such a way that would architecturally require a TLB flush, the TLBs are updated so that, after VM entry, the logical processor will not use any translations that were cached before the transition. The SDM is unclear about when the TLB flush should occur, and whether or not a failed VM entry would flush the TLB, so it is safer to always do the TLB flush in this case. More concretely, KVM also updates the last VPID L1 used for L2 in nested_vmx_transition_tlb_flush() (i.e. last_vpid), even if the VM entry ultimately fails. With the current code, KVM could miss a TLB flush if L1 changes L2's VPID, then does a failed VM entry followed by a successful one, as the failed VM entry would update last_vpid but not actually flush the TLB. Servicing local TLB flushes on failed VM entries makes sure that the TLB is always flushed when last_vpid is updated.
- CVSS
- 9.3 CRITICAL (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Received
- Record last updated
- Sep 16, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from 5c614b3583e7b6dab0c86356fa36c2bcbb8322a0 before c0c66cd575e31218da6a7d104c6ef80b0830b60c; from 5c614b3583e7b6dab0c86356fa36c2bcbb8322a0 before 1025b938dc439b75c720a568a855a13eeb245686; from 5c614b3583e7b6dab0c86356fa36c2bcbb8322a0 before 312cdb6d8940827dea63a7a52fb714a5049f06d1; from 5c614b3583e7b6dab0c86356fa36c2bcbb8322a0 before f74fccdf4f7fb0780cd84944108d35f3d9dc46a7; from 5c614b3583e7b6dab0c86356fa36c2bcbb8322a0 before c43563e7518e65ec6ccaa6a65f84c5af5ca5d379; from 5c614b3583e7b6dab0c86356fa36c2bcbb8322a0 before 62c3ee4c9f0e2efef5157358b3549e50ede96d73; 5c614b3583e7b6dab0c86356fa36c2bcbb8322a0 builds before 05a0b701d1089fb57beeb8982f23c3bbafe0fa8b | CNA record |
References
- https://git.kernel.org/stable/c/c0c66cd575e31218da6a7d104c6ef80b0830b60c
- https://git.kernel.org/stable/c/1025b938dc439b75c720a568a855a13eeb245686
- https://git.kernel.org/stable/c/312cdb6d8940827dea63a7a52fb714a5049f06d1
- https://git.kernel.org/stable/c/f74fccdf4f7fb0780cd84944108d35f3d9dc46a7
- https://git.kernel.org/stable/c/c43563e7518e65ec6ccaa6a65f84c5af5ca5d379
- https://git.kernel.org/stable/c/62c3ee4c9f0e2efef5157358b3549e50ede96d73
- https://git.kernel.org/stable/c/05a0b701d1089fb57beeb8982f23c3bbafe0fa8b
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.