CVE-2024-36881

Kernel warning via stale userfaultfd write protection

Published May 30, 2024 · Updated May 23, 2026

Improper page-table cleanup in affected Linux kernel versions allows local users to trigger a warning via userfaultfd close. When the last userfaultfd reference is closed, the release path fails to clear UFFD write-protect bits from relevant page-table entries as UFFDIO_UNREGISTER does. The gate is local low-privilege access to userfaultfd; the published user-visible consequence is leftover write-protect state and a kernel warning, not data access or code execution.

CVSS severity5.5
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 page-table cleanup in affected Linux kernel versions allows local users to trigger a warning via userfaultfd close. When the last userfaultfd reference is closed, the release path fails to clear UFFD write-protect bits from relevant page-table entries as UFFDIO_UNREGISTER does. The gate is local low-privilege access to userfaultfd; the published user-visible consequence is leftover write-protect state and a kernel warning, not data access or code execution.

The record

CVE
CVE-2024-36881
Published
May 30, 2024
Updated
May 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 30, 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=3e2747c3ddfa717697c3cc2aa6ab989e48d6587d
  2. Affected versionversion=5.19.6 <5.20
  3. Affected versionversion=6.0
  4. Affected versionversion=f369b07c861435bd812a9d14493f71b34132ed6f <377f3a9a3d032a52325a5b110379a25dd1ab1931
  5. Affected versionversion=f369b07c861435bd812a9d14493f71b34132ed6f <8d8b68a5b0c9fb23d37df06bb273ead38fd5a29d
  6. Affected versionversion=f369b07c861435bd812a9d14493f71b34132ed6f <c88033efe9a391e72ba6b5df4b01d6e628f4e734

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3e2747c3ddfa717697c3cc2aa6ab989e48d6587d; version=5.19.6 <5.20; version=6.0; version=f369b07c861435bd812a9d14493f71b34132ed6f <377f3a9a3d032a52325a5b110379a25dd1ab1931; version=f369b07c861435bd812a9d14493f71b34132ed6f <8d8b68a5b0c9fb23d37df06bb273ead38fd5a29d; version=f369b07c861435bd812a9d14493f71b34132ed6f <c88033efe9a391e72ba6b5df4b01d6e628f4e734

Published CVSS scores

5.5CISA-ADPCVSS: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

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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