CVE-2021-46919

Service interruption via enabled-device work-queue resize

Published Feb 27, 2024 · Updated May 11, 2026

Improper state validation in Linux kernel 5.6 allows local users to interrupt service via an IDXD work-queue resize. The wq_size_store handler in drivers/dma/idxd/sysfs.c checks only the work-queue state and accepts a size change when that queue is disabled but its parent device is enabled. Write access to the sysfs size attribute and compatible IDXD hardware are required; public sources do not specify whether interruption causes a hang, crash, or reboot.

CVSS severity5.5
Medium
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper state validation in Linux kernel 5.6 allows local users to interrupt service via an IDXD work-queue resize. The wq_size_store handler in drivers/dma/idxd/sysfs.c checks only the work-queue state and accepts a size change when that queue is disabled but its parent device is enabled. Write access to the sysfs size attribute and compatible IDXD hardware are required; public sources do not specify whether interruption causes a hang, crash, or reboot.

The record

CVE
CVE-2021-46919
Published
Feb 27, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
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=5.6
  2. Affected versionversion=c52ca478233c172b2d322b5241d6279a8661cbba <05b7791c4c4aa8304368fdc55ae911f6b34e7281
  3. Affected versionversion=c52ca478233c172b2d322b5241d6279a8661cbba <0fff71c5a311e1264988179f7dcc217fda15fadd
  4. Affected versionversion=c52ca478233c172b2d322b5241d6279a8661cbba <4ecf25595273203010bc8318c4aee60ad64037ae

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.6; version=c52ca478233c172b2d322b5241d6279a8661cbba <05b7791c4c4aa8304368fdc55ae911f6b34e7281; version=c52ca478233c172b2d322b5241d6279a8661cbba <0fff71c5a311e1264988179f7dcc217fda15fadd; version=c52ca478233c172b2d322b5241d6279a8661cbba <4ecf25595273203010bc8318c4aee60ad64037ae

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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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