CVE-2021-46953

System crash via unchecked interrupt unmapping

Published Feb 27, 2024 · Updated May 11, 2026

Improper interrupt handling in affected Linux kernels allows local users with firmware-control privileges to crash ARM64 systems via invalid firmware. The ACPI GTDT probe error path unregisters an interrupt without confirming that its mapping succeeded, so an illegal interrupt in the GIC SGI range can unmap an IPI. Exploitation requires privileged control of firmware properties; a later IPI send can trigger a kernel crash and interrupt the system.

CVSS severity6.7
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper interrupt handling in affected Linux kernels allows local users with firmware-control privileges to crash ARM64 systems via invalid firmware. The ACPI GTDT probe error path unregisters an interrupt without confirming that its mapping succeeded, so an illegal interrupt in the GIC SGI range can unmap an IPI. Exploitation requires privileged control of firmware properties; a later IPI send can trigger a kernel crash and interrupt the system.

The record

CVE
CVE-2021-46953
Published
Feb 27, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Feb 27, 2024CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=4.12
  2. Affected versionversion=ca9ae5ec4ef0ed13833b03297ab319676965492c <1ecd5b129252249b9bc03d7645a7bda512747277
  3. Affected versionversion=ca9ae5ec4ef0ed13833b03297ab319676965492c <42e69521ee1fa5abf21f478d147d06bbfe6bf6a8
  4. Affected versionversion=ca9ae5ec4ef0ed13833b03297ab319676965492c <504632a3577a049dd9bb7aabae5b4476f9c586b4
  5. Affected versionversion=ca9ae5ec4ef0ed13833b03297ab319676965492c <596e079c362ac17ed02aa1b99fdc444d62072a01
  6. Affected versionversion=ca9ae5ec4ef0ed13833b03297ab319676965492c <7b2162db1498c71962a4bb2f776fa4e76d4d305b
  7. Affected versionversion=ca9ae5ec4ef0ed13833b03297ab319676965492c <c3385a9122f8db15b453e07bfc88117fce7f3724
  8. Affected versionversion=ca9ae5ec4ef0ed13833b03297ab319676965492c <e0f2d86481eaa83df33b0793f75212919db7a19d

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=4.12; version=ca9ae5ec4ef0ed13833b03297ab319676965492c <1ecd5b129252249b9bc03d7645a7bda512747277; version=ca9ae5ec4ef0ed13833b03297ab319676965492c <42e69521ee1fa5abf21f478d147d06bbfe6bf6a8; version=ca9ae5ec4ef0ed13833b03297ab319676965492c <504632a3577a049dd9bb7aabae5b4476f9c586b4; version=ca9ae5ec4ef0ed13833b03297ab319676965492c <596e079c362ac17ed02aa1b99fdc444d62072a01; version=ca9ae5ec4ef0ed13833b03297ab319676965492c <7b2162db1498c71962a4bb2f776fa4e76d4d305b; version=ca9ae5ec4ef0ed13833b03297ab319676965492c <c3385a9122f8db15b453e07bfc88117fce7f3724; version=ca9ae5ec4ef0ed13833b03297ab319676965492c <e0f2d86481eaa83df33b0793f75212919db7a19d

Published CVSS scores

6.7NVDCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

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 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

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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