CVE-2026-89757Hinoki check available

Memory retention via poisoned folio lock count

Published Sep 11, 2026 · Updated Sep 11, 2026

Memory-management error in Linux 6.1 allows local users to retain unevictable pages and inflate locked-memory accounting through MGLRU. The sort_folio() shortcut removes an unevictable folio from its generation list without initializing mlock_count, so the field aliases LIST_POISON2. Reaching the flaw requires MGLRU handling followed by munlock; PG_mlocked and inflated accounting persist until the folio is freed.

CVSS severityUnavailable
Unscored
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Memory-management error in Linux 6.1 allows local users to retain unevictable pages and inflate locked-memory accounting through MGLRU. The sort_folio() shortcut removes an unevictable folio from its generation list without initializing mlock_count, so the field aliases LIST_POISON2. Reaching the flaw requires MGLRU handling followed by munlock; PG_mlocked and inflated accounting persist until the folio is freed.

The record

CVE
CVE-2026-89757
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 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=6.1
  2. Affected versionversion=ac35a490237446b71e3b4b782b1596967edd0aa8 <15d3a2a71c8bf7333d019d249ee33669e69e4275
  3. Affected versionversion=ac35a490237446b71e3b4b782b1596967edd0aa8 <54a58d6656dd403b686b247f0bad8507cbfb45df
  4. Affected versionversion=ac35a490237446b71e3b4b782b1596967edd0aa8 <f7e698e326b239a91ea15844817551921209e826

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=6.1; version=ac35a490237446b71e3b4b782b1596967edd0aa8 <15d3a2a71c8bf7333d019d249ee33669e69e4275; version=ac35a490237446b71e3b4b782b1596967edd0aa8 <54a58d6656dd403b686b247f0bad8507cbfb45df; version=ac35a490237446b71e3b4b782b1596967edd0aa8 <f7e698e326b239a91ea15844817551921209e826

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

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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