CVE-2026-80665

Host crash via unresolved nested VNCR translation

Published Aug 28, 2026 · Updated Aug 28, 2026

Improper fault handling in arm64 KVM nested virtualization in Linux 6.16 allows guest OS users to crash the host via a VNCR fault. When kvm_translate_vncr() returns EFAULT for an unresolved PFN, kvm_handle_vncr_abort() assumes the stage-1 walk result already contains an abort and reaches a BUG_ON when it does not. Exploitation requires an arm64 nested-virtualization guest to fault a VNCR address whose translated GFN lies outside the configured memory slots, interrupting the host system.

CVSS severityUnavailable
Unscored
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper fault handling in arm64 KVM nested virtualization in Linux 6.16 allows guest OS users to crash the host via a VNCR fault. When kvm_translate_vncr() returns EFAULT for an unresolved PFN, kvm_handle_vncr_abort() assumes the stage-1 walk result already contains an abort and reaches a BUG_ON when it does not. Exploitation requires an arm64 nested-virtualization guest to fault a VNCR address whose translated GFN lies outside the configured memory slots, interrupting the host system.

The record

CVE
CVE-2026-80665
Published
Aug 28, 2026
Updated
Aug 28, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Aug 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 28, 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.

  1. Affected versionversion=2a359e072596fcb2e9e85017a865e3618a2fe5b5 <4ead4def04659739c399bfcb063f8a906194c79f
  2. Affected versionversion=2a359e072596fcb2e9e85017a865e3618a2fe5b5 <53804b6839573c9c6fff5f4cf075d6746267345e
  3. Affected versionversion=2a359e072596fcb2e9e85017a865e3618a2fe5b5 <9f3e83345a56280efffe235c65593c7e544c0fcc
  4. Affected versionversion=6.16

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=2a359e072596fcb2e9e85017a865e3618a2fe5b5 <4ead4def04659739c399bfcb063f8a906194c79f; version=2a359e072596fcb2e9e85017a865e3618a2fe5b5 <53804b6839573c9c6fff5f4cf075d6746267345e; version=2a359e072596fcb2e9e85017a865e3618a2fe5b5 <9f3e83345a56280efffe235c65593c7e544c0fcc; version=6.16

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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