CVE-2026-45985

Stale data disclosure via incorrect extent conversion

Published May 27, 2026 · Updated May 27, 2026

Information disclosure in Linux Kernel ext4 allows local users to read stale disk data after a failed direct I/O write. ext4_split_convert_extents() passes EXT4_GET_BLOCKS_CONVERT while splitting an unwritten extent, so ENOSPC can mark the full on-disk extent written after zeroing only its first half and leave the extent-status tree inconsistent. Exposure requires dioread_nolock, a write into the latter part of an unwritten extent, temporary ENOSPC, failed direct I/O, and eviction of the cached extent entry.

CVSS severity5.5
Medium
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Linux Kernel ext4 allows local users to read stale disk data after a failed direct I/O write. ext4_split_convert_extents() passes EXT4_GET_BLOCKS_CONVERT while splitting an unwritten extent, so ENOSPC can mark the full on-disk extent written after zeroing only its first half and leave the extent-status tree inconsistent. Exposure requires dioread_nolock, a write into the latter part of an unwritten extent, temporary ENOSPC, failed direct I/O, and eviction of the cached extent entry.

The record

CVE
CVE-2026-45985
Published
May 27, 2026
Updated
May 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1005
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 27, 2026CVE publishedPublication date reported by the CVE source.
  2. May 27, 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=3.15
  2. Affected versionversion=b8a8684502a0fc852afa0056c6bb2a9273f6fcc0 <2698731d25823267c29190cb578da9296a0c0d7b
  3. Affected versionversion=b8a8684502a0fc852afa0056c6bb2a9273f6fcc0 <2920ec61c98b9476781359f05b94da84e80f54d4
  4. Affected versionversion=b8a8684502a0fc852afa0056c6bb2a9273f6fcc0 <37555690f39f78ef69af347d9aff897e07445949
  5. Affected versionversion=b8a8684502a0fc852afa0056c6bb2a9273f6fcc0 <67cdb7bd7442bd3cdc6d6088bbb2df9be2fe936c
  6. Affected versionversion=b8a8684502a0fc852afa0056c6bb2a9273f6fcc0 <716e7439a5a9b18c3ff882c2f8c834b9ced1aaec
  7. Affected versionversion=b8a8684502a0fc852afa0056c6bb2a9273f6fcc0 <77e407967cd872cd75d7e4a691908e49c8e6b4d4
  8. Affected versionversion=b8a8684502a0fc852afa0056c6bb2a9273f6fcc0 <feaf2a80e78f89ee8a3464126077ba8683b62791

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=3.15; version=b8a8684502a0fc852afa0056c6bb2a9273f6fcc0 <2698731d25823267c29190cb578da9296a0c0d7b; version=b8a8684502a0fc852afa0056c6bb2a9273f6fcc0 <2920ec61c98b9476781359f05b94da84e80f54d4; version=b8a8684502a0fc852afa0056c6bb2a9273f6fcc0 <37555690f39f78ef69af347d9aff897e07445949; version=b8a8684502a0fc852afa0056c6bb2a9273f6fcc0 <67cdb7bd7442bd3cdc6d6088bbb2df9be2fe936c; version=b8a8684502a0fc852afa0056c6bb2a9273f6fcc0 <716e7439a5a9b18c3ff882c2f8c834b9ced1aaec; version=b8a8684502a0fc852afa0056c6bb2a9273f6fcc0 <77e407967cd872cd75d7e4a691908e49c8e6b4d4; version=b8a8684502a0fc852afa0056c6bb2a9273f6fcc0 <feaf2a80e78f89ee8a3464126077ba8683b62791

Published CVSS scores

5.5NIST NVDCVSS: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

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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

T1005Data from Local System

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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