CVE-2021-46918

Local denial of service via stale MSIX permissions

Published Feb 27, 2024 · Updated May 11, 2026

Improper shutdown state handling in Linux 5.11 before 5.11.16 allows local users to interrupt service through the IDXD driver. The IDXD shutdown path leaves MSI-X permission entries enabled and PASID entries programmed instead of disabling and clearing them as probe setup is unwound. Triggering the availability impact requires local low-privileged access and Intel IDXD hardware using the affected driver; no confidentiality or integrity impact is reported.

CVSS severity5.5
Medium
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper shutdown state handling in Linux 5.11 before 5.11.16 allows local users to interrupt service through the IDXD driver. The IDXD shutdown path leaves MSI-X permission entries enabled and PASID entries programmed instead of disabling and clearing them as probe setup is unwound. Triggering the availability impact requires local low-privileged access and Intel IDXD hardware using the affected driver; no confidentiality or integrity impact is reported.

The record

CVE
CVE-2021-46918
Published
Feb 27, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

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=5.11
  2. Affected versionversion=8e50d392652f20616a136165dff516b86baf5e49 <6df0e6c57dfc064af330071f372f11aa8c584997
  3. Affected versionversion=8e50d392652f20616a136165dff516b86baf5e49 <c84b8982d7aa9b4717dc36a1c6cbc93ee153b500

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.11; version=8e50d392652f20616a136165dff516b86baf5e49 <6df0e6c57dfc064af330071f372f11aa8c584997; version=8e50d392652f20616a136165dff516b86baf5e49 <c84b8982d7aa9b4717dc36a1c6cbc93ee153b500

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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.

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
Privilegesauthenticated
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

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Your stack

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