Linux Kernel up to 6.6.144/6.12.96/6.18.39/7.1.3 KVM arm64 pKVM hyp vCPU flush_hyp_vcpu used_lrs out-of-bounds

CVSS Meta Temp Score
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CTI Interest Score
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8.7$0-$5k2.40-

Summaryinfo

A vulnerability, which was classified as very critical, was found in Linux Kernel up to 6.6.144/6.12.96/6.18.39/7.1.3. This impacts the function flush_hyp_vcpu of the component KVM arm64 pKVM hyp vCPU. Such manipulation of the argument used_lrs leads to out-of-bounds. This vulnerability is traded as CVE-2026-64287. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.144/6.12.96/6.18.39/7.1.3. It has been rated as very critical. Affected by this issue is the function flush_hyp_vcpu of the component KVM arm64 pKVM hyp vCPU. The manipulation of the argument used_lrs with an unknown input leads to a out-of-bounds vulnerability. Using CWE to declare the problem leads to CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2026-64287 since 07/19/2026. The exploitation is known to be easy. The attack may be launched remotely. Additional levels of successful authentication are needed for exploitation. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 07/25/2026).

Upgrading to version 6.6.145, 6.12.97, 6.18.40, 7.1.4 or 7.2-rc1 eliminates this vulnerability. Applying the patch 2c5e72b9fbf83fdfa724e9f1af0f418ccf8739b8/9fa301d8298778dd799fa4dcf7a7f440715d146e/c646431865f4b1a5b14067233fa27b11e05e0d46/7fca3fcef81c713bc82a37bf741e0f28e6d04a6f/8cc8bbbfab14c22c5551d0dd19b208a44b141c76 is able to eliminate this problem.

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Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.1
VulDB Meta Temp Score: 8.7

VulDB Base Score: 9.1
VulDB Temp Score: 8.7
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.6.145/6.12.97/6.18.40/7.1.4/7.2-rc1
Patch: 2c5e72b9fbf83fdfa724e9f1af0f418ccf8739b8/9fa301d8298778dd799fa4dcf7a7f440715d146e/c646431865f4b1a5b14067233fa27b11e05e0d46/7fca3fcef81c713bc82a37bf741e0f28e6d04a6f/8cc8bbbfab14c22c5551d0dd19b208a44b141c76

Timelineinfo

07/19/2026 CVE reserved
07/25/2026 +6 days Advisory disclosed
07/25/2026 +0 days VulDB entry created
07/25/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-64287 (🔒)
GCVE (CVE): GCVE-0-2026-64287
GCVE (VulDB): GCVE-100-383084

Entryinfo

Created: 07/25/2026 13:43
Changes: 07/25/2026 13:43 (60)
Complete: 🔍
Cache ID: 216::103

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