CVE-2026-64287: Linux kernel · KVM: arm64: Bound used_lrs when flushing the pKVM hyp vCPU
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.2 High · fixed in 7.0.0-1012.12~24.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 15:59 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 7.0.0-1012.12~24.04.1, 7.0.0-1011.11~24.04.1, 7.0.0-31.31~24.04.1 +7
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
An official patch is available and should be applied by updating to linux-hwe-edge kernel versions 7.0.0-31.31 or later as provided by the Ubuntu security advisories USN-8726-1 and USN-8727-1. After updating, a system reboot is required. Due to ABI changes, recompilation and reinstallation of third-party kernel modules may be necessary. Follow vendor instructions for updating and rebuilding kernel modules.
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.
References
- nvd.nist.gov/vuln/detail/CVE-2026-64287 (opens in a new tab)
- git.kernel.org/stable/c/2c5e72b9fbf83fdfa724e9f1af0f418ccf8739b8 (opens in a new tab)
- git.kernel.org/stable/c/7fca3fcef81c713bc82a37bf741e0f28e6d04a6f (opens in a new tab)
- git.kernel.org/stable/c/8cc8bbbfab14c22c5551d0dd19b208a44b141c76 (opens in a new tab)
- git.kernel.org/stable/c/9fa301d8298778dd799fa4dcf7a7f440715d146e (opens in a new tab)
- git.kernel.org/stable/c/c646431865f4b1a5b14067233fa27b11e05e0d46 (opens in a new tab)
- ubuntu.com/security/CVE-2026-64287 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64287 (opens in a new tab)
- git.kernel.org/linus/8cc8bbbfab14c22c5551d0dd19b208a44b141c76 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)