KVM: arm64: Bound used_lrs when flushing the pKVM hyp vCPU (CVE-2026-64287) | HOL Guard CVE

High · CVSS 8.2CVE-2026-64287

KVM: arm64: Bound used_lrs when flushing the pKVM hyp vCPU

Answer in brief

CVE-2026-64287 records a High severity (CVSS 8.2) vulnerability in KVM: arm64: Bound used_lrs when flushing the pKVM hyp vCPU. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Jul 25, 2026Updated Aug 17, 2026Source checked Sep 20, 2026First seen by HOL Aug 5, 2026Material review Aug 17, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 8.2
Exploitation: Not marked as known exploited
Affected software: 3 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 8.2. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Affected products and reported versions
Product	Affected versions	Fixed versions
cpe:2.3:o:linux:linux_kernel::::::::	Not reported	Not reported

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=be66e67f175096f283c9d5614c4991fc9e7ed975 <2c5e72b9fbf83fdfa724e9f1af0f418ccf8739b8 \|\| >=be66e67f175096f283c9d5614c4991fc9e7ed975 <9fa301d8298778dd799fa4dcf7a7f440715d146e \|\| >=be66e67f175096f283c9d5614c4991fc9e7ed975 <c646431865f4b1a5b14067233fa27b11e05e0d46 \|\| >=be66e67f175096f283c9d5614c4991fc9e7ed975 <7fca3fcef81c713bc82a37bf741e0f28e6d04a6f \|\| >=be66e67f175096f283c9d5614c4991fc9e7ed975 <8cc8bbbfab14c22c5551d0dd19b208a44b141c76	2c5e72b9fbf83fdfa724e9f1af0f418ccf8739b8, 9fa301d8298778dd799fa4dcf7a7f440715d146e, c646431865f4b1a5b14067233fa27b11e05e0d46, 7fca3fcef81c713bc82a37bf741e0f28e6d04a6f, 8cc8bbbfab14c22c5551d0dd19b208a44b141c76
Linux/Linuxgeneric	6.2	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 2c5e72b9fbf83fdfa724e9f1af0f418ccf8739b8 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Jul 25, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 5, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Bound used_lrs when flushing the pKVM hyp vCPU flush_hyp_vcpu() copies the host vGIC state into the hyp's private vCPU on every run. The vGIC list register save and restore use used_lrs as their loop bound and expect it to stay within the number of implemented list registers. While this is generally the case, flush_hyp_vcpu() copies vgic_v3 verbatim and does not enforce this, so a value provided by the host is used at EL2 to index vgic_lr[] and access ICH_LR<n>_EL2 (host -> EL2). Fix by clamping used_lrs to the number of implemented list registers after the copy, as the trusted path already does in vgic_flush_lr_state(). The number of implemented list registers is constant after init, so it is replicated once from kvm_vgic_global_state.nr_lr into hyp_gicv3_nr_lr rather than read on every entry.

Quoted source text, attributed separately from HOL analysis.