CVE-2026-46121

Freed kernel memory access via memcg_path race

Published May 28, 2026 · Updated May 28, 2026

Use-after-free in the Linux Kernel DAMON sysfs interface allows local users to access freed kernel memory through concurrent file operations. Direct reads and writes of damon_sysfs_scheme_filter->memcg_path use separate open files without damon_sysfs_lock, so a writer can free the buffer while a reader accesses it. Access to the privileged DAMON sysfs controls and separate open files is required; kernfs serializes operations that share one open file.

CVSS severity7.8
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the Linux Kernel DAMON sysfs interface allows local users to access freed kernel memory through concurrent file operations. Direct reads and writes of damon_sysfs_scheme_filter->memcg_path use separate open files without damon_sysfs_lock, so a writer can free the buffer while a reader accesses it. Access to the privileged DAMON sysfs controls and separate open files is required; kernfs serializes operations that share one open file.

The record

CVE
CVE-2026-46121
Published
May 28, 2026
Updated
May 28, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-416, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 28, 2026CVE publishedPublication date reported by the CVE source.
  2. May 28, 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=490a43d07f1663d827e802720d30cbc0494e4f81 <b1e9f2d5870776347edef927f9bb3ea19b8e3abb
  2. Affected versionversion=4a158ac0538dd5695eeaa00aa0720d711f3e4ef1
  3. Affected versionversion=4f489fe6afb395dbc79840efa3c05440b760d883 <1e68eb96e8beb1abefd12dd22c5637795d8a877e
  4. Affected versionversion=4f489fe6afb395dbc79840efa3c05440b760d883 <baecc45ad60e621ef14d6c1e7f41ef36bbfdf910
  5. Affected versionversion=4f489fe6afb395dbc79840efa3c05440b760d883 <eafd6f5372d29b0dd213799b92c2c9c7ad31d7da
  6. Affected versionversion=6.12.36 <6.12.88
  7. Affected versionversion=6.15.5 <6.16
  8. Affected versionversion=6.16
  9. Affected versionversion=6.6.96 <6.6.140
  10. Affected versionversion=c5d5b0047b0c0f304608f3824139f7bd34c48413 <c88802d0e8edd14b6cd2daf3000f99adbc4c85c5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=490a43d07f1663d827e802720d30cbc0494e4f81 <b1e9f2d5870776347edef927f9bb3ea19b8e3abb; version=4a158ac0538dd5695eeaa00aa0720d711f3e4ef1; version=4f489fe6afb395dbc79840efa3c05440b760d883 <1e68eb96e8beb1abefd12dd22c5637795d8a877e; version=4f489fe6afb395dbc79840efa3c05440b760d883 <baecc45ad60e621ef14d6c1e7f41ef36bbfdf910; version=4f489fe6afb395dbc79840efa3c05440b760d883 <eafd6f5372d29b0dd213799b92c2c9c7ad31d7da; version=6.12.36 <6.12.88; version=6.15.5 <6.16; version=6.16; version=6.6.96 <6.6.140; version=c5d5b0047b0c0f304608f3824139f7bd34c48413 <c88802d0e8edd14b6cd2daf3000f99adbc4c85c5

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1068Exploitation for Privilege Escalation

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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