CVE-2026-45912

Local service interruption via stale ext4 extent cache

Published May 27, 2026 · Updated May 27, 2026

Space-accounting corruption in Linux Kernel allows local users to interrupt service through writes to unwritten ext4 extents. During ext4_split_extent_at(), extent lookup and caching can record the truncated half as a hole while an unwritten extent is split, and no caller replaces the stale status. A local user needs write access to an ext4 filesystem and a direct-I/O write followed by a delayed buffered write; the resulting status conflict corrupts space accounting and interrupts service.

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

Space-accounting corruption in Linux Kernel allows local users to interrupt service through writes to unwritten ext4 extents. During ext4_split_extent_at(), extent lookup and caching can record the truncated half as a hole while an unwritten extent is split, and no caller replaces the stale status. A local user needs write access to an ext4 filesystem and a direct-I/O write followed by a delayed buffered write; the resulting status conflict corrupts space accounting and interrupts service.

The record

CVE
CVE-2026-45912
Published
May 27, 2026
Updated
May 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499
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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <5.10.252
  2. Affected versionversion=0 <5.15.202
  3. Affected versionversion=0 <6.1.165
  4. Affected versionversion=0 <6.12.75
  5. Affected versionversion=0 <6.18.14
  6. Affected versionversion=0 <6.19.4
  7. Affected versionversion=0 <6.6.128
  8. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4c2d9dac4d328244f9365b0a1fa27ec802821820
  9. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <5b1f4290453314e11cd8e15c7baa8a9b76c19b23
  10. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <692103feca376ae4298c92aa8828015d20f1d87b
  11. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8302b5b4aacdbb378f7b1216bb2ee782b5142415
  12. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8b4b19a2f96348d70bfa306ef7d4a13b0bcbea79
  13. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <93b2ebbbcb2e63cfc21a1946dfe91d3aa7952036
  14. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <96007fd3c106aea773c1afae2d6f64cceb6da208
  15. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9a2b95cdaf07785e2739199037bd9c0863ccc1be

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=0 <5.10.252; version=0 <5.15.202; version=0 <6.1.165; version=0 <6.12.75; version=0 <6.18.14; version=0 <6.19.4; version=0 <6.6.128; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4c2d9dac4d328244f9365b0a1fa27ec802821820; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <5b1f4290453314e11cd8e15c7baa8a9b76c19b23; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <692103feca376ae4298c92aa8828015d20f1d87b; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8302b5b4aacdbb378f7b1216bb2ee782b5142415; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8b4b19a2f96348d70bfa306ef7d4a13b0bcbea79; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <93b2ebbbcb2e63cfc21a1946dfe91d3aa7952036; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <96007fd3c106aea773c1afae2d6f64cceb6da208; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9a2b95cdaf07785e2739199037bd9c0863ccc1be

Published CVSS scores

5.5NVDCVSS: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

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

T1499Endpoint Denial of Service

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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