Cross-VM stale translation reuse via unflushed VPID
Published Sep 16, 2026 · Updated Sep 16, 2026
Improper TLB invalidation in Linux KVM nVMX allows guest OS users to reuse stale translations after nested VMX reinitialization. The vpid02 allocator leaves last_vpid unchanged after VMXOFF, so the first VM-Enter after VMXON can skip the required TLB flush when a VPID is recycled. Reachability requires an L1 guest hypervisor to execute VMXOFF then VMXON, run an L2 guest, and receive a VPID whose physical-CPU TLB entries came from another vCPU or VM.
Summary
What happened
Improper TLB invalidation in Linux KVM nVMX allows guest OS users to reuse stale translations after nested VMX reinitialization. The vpid02 allocator leaves last_vpid unchanged after VMXOFF, so the first VM-Enter after VMXON can skip the required TLB flush when a VPID is recycled. Reachability requires an L1 guest hypervisor to execute VMXOFF then VMXON, run an L2 guest, and receive a VPID whose physical-CPU TLB entries came from another vCPU or VM.
The record
- CVE
- CVE-2026-89932
- Published
- Sep 16, 2026
- Updated
- Sep 16, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- Unavailable
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Sep 16, 2026CVE publishedPublication date reported by the CVE source.
- Sep 16, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <5.15.221
- Affected versionversion=0 <6.1.188
- Affected versionversion=0 <6.12.110
- Affected versionversion=0 <6.18.51
- Affected versionversion=0 <6.6.157
- Affected versionversion=0 <7.2.5
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <121991d150735f3c0f7401678ce4d35c5b4ac898
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <22dfcc22c95e91295119a1c3b469816ce44c4804
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <26de0d2d9a8d14c03e5ebb25fd68b5bfcd5ac366
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <62604376c313178811375f40a282fc2a46cd2311
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8b98d662ab24f34710a56e03bc9169e4a5508606
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8bc609999ec223089fec8d74c7de27d689606b36
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f0772389413dce9657c7d6950abf3edbbd511356
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
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Public exploit references
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Technologies
Your stack
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Your stack
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