CVE-2026-31597

Kernel compromise via OCFS2 fault race

Published Apr 24, 2026 · Updated Apr 24, 2026

Use-after-free in Linux Kernel OCFS2 allows local users to trigger an unsafe kernel-memory dereference by racing a page fault with unmapping. When filemap_fault() returns VM_FAULT_RETRY after dropping mmap_lock, concurrent munmap() can free the vm_area_struct while ocfs2_fault() retains its vma pointer, which trace_ocfs2_fault() then dereferences. The path requires low-privileged local access to a mapped OCFS2 file; successful exploitation compromises kernel confidentiality, integrity, and availability.

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 Linux Kernel OCFS2 allows local users to trigger an unsafe kernel-memory dereference by racing a page fault with unmapping. When filemap_fault() returns VM_FAULT_RETRY after dropping mmap_lock, concurrent munmap() can free the vm_area_struct while ocfs2_fault() retains its vma pointer, which trace_ocfs2_fault() then dereferences. The path requires low-privileged local access to a mapped OCFS2 file; successful exploitation compromises kernel confidentiality, integrity, and availability.

The record

CVE
CVE-2026-31597
Published
Apr 24, 2026
Updated
Apr 24, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-416
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 24, 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4cf2768a0291a0cdd0dae801ea0eafa3878a349d
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <76a602fdbb78dd05b2da06f74a988cebc97e82d0
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <925bf22c1b823e231b1baea761fe8a1512e442f2
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <d45ff441b416d4aa1af72b1db23d959601c04da2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4cf2768a0291a0cdd0dae801ea0eafa3878a349d; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <76a602fdbb78dd05b2da06f74a988cebc97e82d0; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <925bf22c1b823e231b1baea761fe8a1512e442f2; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <d45ff441b416d4aa1af72b1db23d959601c04da2

Published CVSS scores

7.8kernel.orgCVSS: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

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free

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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