CVE-2023-53813

System crash via skipped ext4 preallocation traversal

Published Dec 9, 2025 · Updated May 11, 2026

Denial of service in Linux kernel 6.4 allows local users to crash the system through concurrent ext4 preallocation activity. ext4_mb_use_preallocated directly traverses a per-inode rbtree while concurrent discard can mark entries deleted, causing it to skip a usable preallocation and create an overlap that reaches BUG_ON. A local user must drive concurrent allocation and preallocation discard activity on an ext4 filesystem; the documented consequence is a kernel crash.

CVSS severity7.0
High
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Linux kernel 6.4 allows local users to crash the system through concurrent ext4 preallocation activity. ext4_mb_use_preallocated directly traverses a per-inode rbtree while concurrent discard can mark entries deleted, causing it to skip a usable preallocation and create an overlap that reaches BUG_ON. A local user must drive concurrent allocation and preallocation discard activity on an ext4 filesystem; the documented consequence is a kernel crash.

The record

CVE
CVE-2023-53813
Published
Dec 9, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 9, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=3872778664e36528caf8b27f355e75482f6d562d <339fee69a1daa71d6f97e47a867e2c32419a2406
  2. Affected versionversion=3872778664e36528caf8b27f355e75482f6d562d <9d3de7ee192a6a253f475197fe4d2e2af10a731f
  3. Affected versionversion=6.4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3872778664e36528caf8b27f355e75482f6d562d <339fee69a1daa71d6f97e47a867e2c32419a2406; version=3872778664e36528caf8b27f355e75482f6d562d <9d3de7ee192a6a253f475197fe4d2e2af10a731f; version=6.4

Published CVSS scores

7.0Amazon LinuxCVSS:3.1/AV:L/AC:H/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.

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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.

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Technologies

Your stack

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Your stack

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