KVM: arm64: Clear __hyp_running_vcpu when flushing the pKVM hyp vCPU (CVE-2026-64286) | HOL Guard CVE

High · CVSS 8.2CVE-2026-64286

KVM: arm64: Clear __hyp_running_vcpu when flushing the pKVM hyp vCPU

Answer in brief

CVE-2026-64286 records a High severity (CVSS 8.2) vulnerability in KVM: arm64: Clear __hyp_running_vcpu 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 <477145860dba4c30f0b4e36f02f4c5291c1c888b \|\| >=be66e67f175096f283c9d5614c4991fc9e7ed975 <dfaef40d8a1533940fc1af788d70fce07362b4ce \|\| >=be66e67f175096f283c9d5614c4991fc9e7ed975 <6bea2f8becdb20d34378493c3b77a9b9cf8c6cfa \|\| >=be66e67f175096f283c9d5614c4991fc9e7ed975 <d4f4d61715d1061ba83b88196a3605662be30750 \|\| >=be66e67f175096f283c9d5614c4991fc9e7ed975 <e8042f6e1d7befb2fb6b10a75918642bcd0acf9a	477145860dba4c30f0b4e36f02f4c5291c1c888b, dfaef40d8a1533940fc1af788d70fce07362b4ce, 6bea2f8becdb20d34378493c3b77a9b9cf8c6cfa, d4f4d61715d1061ba83b88196a3605662be30750, e8042f6e1d7befb2fb6b10a75918642bcd0acf9a
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 477145860dba4c30f0b4e36f02f4c5291c1c888b 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: Clear __hyp_running_vcpu when flushing the pKVM hyp vCPU flush_hyp_vcpu() copies the host vCPU context into the hyp's private vCPU on every run. ctxt_to_vcpu() expects a guest context to have a NULL __hyp_running_vcpu, which is only ever set on the host context, so that it resolves the vCPU via container_of(). While this is generally the case, flush_hyp_vcpu() copies the context verbatim and does not enforce this, so a value provided by the host is dereferenced at EL2 (host -> EL2). Fix by clearing __hyp_running_vcpu after the copy.

Quoted source text, attributed separately from HOL analysis.