CVE-2026-98546

Local host crash via misconfigured register trapping

Published Oct 18, 2026 · Updated Oct 18, 2026

Incorrect register trapping in Linux Arm64 boot code allows local users to crash the host through a PMZR_EL0 register write. The __init_el2_fgt2() routine reuses a read-trap mask for HDFGWTR2_EL2, leaving the write-only register's trap enabled and sending writes to an unhandled nVHE hypervisor path that executes BUG(). Exposure requires applicable PMUv3p9 hardware, kernel.perf_user_access=1, and a task with a user-read performance event; the resulting failure brings down the host without a panic message.

CVSS severityUnavailable
Unscored
EPSS probability0.20%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect register trapping in Linux Arm64 boot code allows local users to crash the host through a PMZR_EL0 register write. The __init_el2_fgt2() routine reuses a read-trap mask for HDFGWTR2_EL2, leaving the write-only register's trap enabled and sending writes to an unhandled nVHE hypervisor path that executes BUG(). Exposure requires applicable PMUv3p9 hardware, kernel.perf_user_access=1, and a task with a user-read performance event; the resulting failure brings down the host without a panic message.

The record

CVE
CVE-2026-98546
Published
Oct 18, 2026
Updated
Oct 18, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 18, 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=6.12.25 <6.12.112
  2. Affected versionversion=6.14.4 <6.15
  3. Affected versionversion=6.15
  4. Affected versionversion=686d8f7b592f3466f44aea653c8147611b351c83 <bb8c90c86441c090e9036f019cf1b4d7894a2c40
  5. Affected versionversion=858c7bfcb35e1100b58bb63c9f562d86e09418d9 <071f51188a5d8ec10535541255587976d12fc7d8
  6. Affected versionversion=858c7bfcb35e1100b58bb63c9f562d86e09418d9 <2bc6b218717b9d08f466f88209251d54bc09b207
  7. Affected versionversion=858c7bfcb35e1100b58bb63c9f562d86e09418d9 <ce71865bf43f88bed9d9218e9218e537150be506
  8. Affected versionversion=882f78400322c0aec4b641a7168adad9a66bc0c2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.12.25 <6.12.112; version=6.14.4 <6.15; version=6.15; version=686d8f7b592f3466f44aea653c8147611b351c83 <bb8c90c86441c090e9036f019cf1b4d7894a2c40; version=858c7bfcb35e1100b58bb63c9f562d86e09418d9 <071f51188a5d8ec10535541255587976d12fc7d8; version=858c7bfcb35e1100b58bb63c9f562d86e09418d9 <2bc6b218717b9d08f466f88209251d54bc09b207; version=858c7bfcb35e1100b58bb63c9f562d86e09418d9 <ce71865bf43f88bed9d9218e9218e537150be506; version=882f78400322c0aec4b641a7168adad9a66bc0c2

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.

Activity data is delayed. The latest report is Sep 28, 2026.

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

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

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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