CVE-2026-45892

Service interruption via stale ext4 extent cache

Published May 27, 2026 · Updated May 27, 2026

Filesystem state inconsistency in Linux Kernel allows local users to interrupt service through buffered writes to an ext4 file. After a failed split zeroes an unwritten extent, ext4_map_create_blocks() updates only part of the extent-status tree and leaves a stale unwritten entry. Reachability requires an extent-based ext4 file, a buffered write with dioread_nolock disabled, and temporary space exhaustion during the first split.

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

What happened

Filesystem state inconsistency in Linux Kernel allows local users to interrupt service through buffered writes to an ext4 file. After a failed split zeroes an unwritten extent, ext4_map_create_blocks() updates only part of the extent-status tree and leaves a stale unwritten entry. Reachability requires an extent-based ext4 file, a buffered write with dioread_nolock disabled, and temporary space exhaustion during the first split.

The record

CVE
CVE-2026-45892
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

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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=0 <6.12.75
  2. Affected versionversion=0 <6.18.14
  3. Affected versionversion=0 <6.19.4
  4. Affected versionversion=0 <6.6.130
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6d882ea3b0931b43530d44149b79fcd4ffc13030
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a1b962a821e7a52d48212ae269b45808b4411267
  7. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c2ee51d684adca7645e4aa74adca13f6750390bc
  8. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <d8ee559fccdef713f058cfe5f2c03dc9b18be3b1
  9. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f0931a5c17005a0c4fc35bd1a001245effc3354b

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=0 <6.12.75; version=0 <6.18.14; version=0 <6.19.4; version=0 <6.6.130; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6d882ea3b0931b43530d44149b79fcd4ffc13030; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a1b962a821e7a52d48212ae269b45808b4411267; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c2ee51d684adca7645e4aa74adca13f6750390bc; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <d8ee559fccdef713f058cfe5f2c03dc9b18be3b1; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f0931a5c17005a0c4fc35bd1a001245effc3354b

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

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 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

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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