CVE-2026-89981

Host panic via disabled-MTE register read

Published Sep 16, 2026 · Updated Sep 16, 2026

Improper register access in the arm64 CPU-information path in Linux 7.0 allows local users to trigger a host kernel panic. The __cpuinfo_store_cpu() path reads GMID_EL1 from a returning CPU based on raw MTE capability even when kernel configuration or arm64.nomte disables MTE. The condition requires pKVM, administrative control, and a CPU offline-online cycle; the resulting undefined-instruction exception panics the host.

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

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper register access in the arm64 CPU-information path in Linux 7.0 allows local users to trigger a host kernel panic. The __cpuinfo_store_cpu() path reads GMID_EL1 from a returning CPU based on raw MTE capability even when kernel configuration or arm64.nomte disables MTE. The condition requires pKVM, administrative control, and a CPU offline-online cycle; the resulting undefined-instruction exception panics the host.

The record

CVE
CVE-2026-89981
Published
Sep 16, 2026
Updated
Sep 16, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
admin

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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=7.0
  2. Affected versionversion=f35abcbb8a084db4c24b66ccc8db0405c08e2f61 <5445d64199626974269fcdf347769ad44b0bb53b
  3. Affected versionversion=f35abcbb8a084db4c24b66ccc8db0405c08e2f61 <d2d22ff377cd43f2e9660426ff22e3cd4c534637

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=7.0; version=f35abcbb8a084db4c24b66ccc8db0405c08e2f61 <5445d64199626974269fcdf347769ad44b0bb53b; version=f35abcbb8a084db4c24b66ccc8db0405c08e2f61 <d2d22ff377cd43f2e9660426ff22e3cd4c534637

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo