CVE-2021-46917

Local information disclosure via WQCFG register clobbering

Published Feb 27, 2024 · Updated May 23, 2026

Improper WQCFG register cleanup in the Linux kernel 5.8 through 5.10.31 and 5.11 through 5.11.15 allows local users to read protected data. The IDXD work-queue cleanup path zeroes the WQCFG MMIO region after reset, overwriting registers rather than issuing the hardware reset command. Exploitation requires local access and an IDXD device using the affected driver; the published record does not identify the protected data exposed by the register corruption.

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 WQCFG register cleanup in the Linux kernel 5.8 through 5.10.31 and 5.11 through 5.11.15 allows local users to read protected data. The IDXD work-queue cleanup path zeroes the WQCFG MMIO region after reset, overwriting registers rather than issuing the hardware reset command. Exploitation requires local access and an IDXD device using the affected driver; the published record does not identify the protected data exposed by the register corruption.

The record

CVE
CVE-2021-46917
Published
Feb 27, 2024
Updated
May 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-668
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 27, 2024CVE publishedPublication date reported by the CVE source.
  2. May 23, 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=2a2df2bd10de44c3804661ed15157817c12d6291
  2. Affected versionversion=5.7.10 <5.8
  3. Affected versionversion=5.8
  4. Affected versionversion=da32b28c95a79e399e18c03f8178f41aec9c66e4 <e5eb9757fe4c2392e069246ae78badc573af1833
  5. Affected versionversion=da32b28c95a79e399e18c03f8178f41aec9c66e4 <ea9aadc06a9f10ad20a90edc0a484f1147d88a7a
  6. Affected versionversion=da32b28c95a79e399e18c03f8178f41aec9c66e4 <f7dc8f5619165e1fa3383d0c2519f502d9e2a1a9

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2a2df2bd10de44c3804661ed15157817c12d6291; version=5.7.10 <5.8; version=5.8; version=da32b28c95a79e399e18c03f8178f41aec9c66e4 <e5eb9757fe4c2392e069246ae78badc573af1833; version=da32b28c95a79e399e18c03f8178f41aec9c66e4 <ea9aadc06a9f10ad20a90edc0a484f1147d88a7a; version=da32b28c95a79e399e18c03f8178f41aec9c66e4 <f7dc8f5619165e1fa3383d0c2519f502d9e2a1a9

Published CVSS scores

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

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

CWE-668Exposure of Resource to Wrong Sphere

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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