CVE-2026-90040

Host crash via stale SEV-SNP VMSA mapping

Published Sep 16, 2026 · Updated Sep 16, 2026

Denial of service in Linux KVM 6.11 allows local users to crash an AMD SEV-SNP host by invalidating a VMSA-backed guest_memfd page. The KVM SEV path leaves control.vmsa_pa bound after its backing page is hole-punched or its memslot is deleted or moved, so firmware rejects RMPUPDATE and the next use faults. Reaching the fault requires local access to operate an SEV-SNP VM on supported AMD hardware, and the bounded consequence documented is a host kernel page fault and crash.

CVSS severityUnavailable
Unscored
EPSS probabilityUnavailable
No score available in this record
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

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Summary

What happened

Denial of service in Linux KVM 6.11 allows local users to crash an AMD SEV-SNP host by invalidating a VMSA-backed guest_memfd page. The KVM SEV path leaves control.vmsa_pa bound after its backing page is hole-punched or its memslot is deleted or moved, so firmware rejects RMPUPDATE and the next use faults. Reaching the fault requires local access to operate an SEV-SNP VM on supported AMD hardware, and the bounded consequence documented is a host kernel page fault and crash.

The record

CVE
CVE-2026-90040
Published
Sep 16, 2026
Updated
Sep 16, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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=6.11
  2. Affected versionversion=e366f92ea99e1961fbad5e2110900e9f4fcb249b <2640cc26ed0dd1bf6ec2f6852a60e494093db3e5
  3. Affected versionversion=e366f92ea99e1961fbad5e2110900e9f4fcb249b <d1a3c216233413f57f5341a9b878b7e2dde7e785

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.11; version=e366f92ea99e1961fbad5e2110900e9f4fcb249b <2640cc26ed0dd1bf6ec2f6852a60e494093db3e5; version=e366f92ea99e1961fbad5e2110900e9f4fcb249b <d1a3c216233413f57f5341a9b878b7e2dde7e785

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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