CVE-2026-43075

Kernel memory corruption via unchecked OCFS2 id_count

Published May 6, 2026 · Updated May 6, 2026

Out-of-bounds write in Linux Kernel OCFS2 allows local users to corrupt kernel memory via a crafted filesystem mounted on a loop device. ocfs2_try_to_write_inline_data trusts the on-disk id_count value when deciding whether inline data fits, allowing ocfs2_write_end_inline to copy beyond the inode block buffer. The filesystem must already be mounted and a copy_file_range splice fallback must reach the inline-write path; the resulting overwrite can corrupt adjacent kernel memory and crash the system.

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

Out-of-bounds write in Linux Kernel OCFS2 allows local users to corrupt kernel memory via a crafted filesystem mounted on a loop device. ocfs2_try_to_write_inline_data trusts the on-disk id_count value when deciding whether inline data fits, allowing ocfs2_write_end_inline to copy beyond the inode block buffer. The filesystem must already be mounted and a copy_file_range splice fallback must reach the inline-write path; the resulting overwrite can corrupt adjacent kernel memory and crash the system.

The record

CVE
CVE-2026-43075
Published
May 6, 2026
Updated
May 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-787, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 6, 2026CVE publishedPublication date reported by the CVE source.
  2. May 6, 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 <0c1af902223b6fcedb60904ca0b551254686c7b9
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <69d3c69ade1e4285ab4ca48fe7acee0767e65604
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7bc5da4842bed3252d26e742213741a4d0ac1b14
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <947f953978b0d9463498d548d0f054f5a75be2e9
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e2c9dc6b6e96f3585f2a1062ca3374a52db0938f

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <0c1af902223b6fcedb60904ca0b551254686c7b9; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <69d3c69ade1e4285ab4ca48fe7acee0767e65604; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <7bc5da4842bed3252d26e742213741a4d0ac1b14; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <947f953978b0d9463498d548d0f054f5a75be2e9; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e2c9dc6b6e96f3585f2a1062ca3374a52db0938f

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

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-787Out-of-bounds Write
T1499.004Endpoint Denial of Service: Application or System Exploitation

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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