CVE-2023-53473Public exploit

Kernel memory disclosure via unchecked ext4 hash errors

Published Oct 1, 2025 · Updated Oct 1, 2025

Unchecked return handling in affected Linux kernel ext4 versions allows local users to disclose kernel memory and corrupt directories. Several ext4 name-lookup and directory-index callers ignore ext4fs_dirhash() errors and continue with zeroed or stale hash fields. The path requires local filesystem operations involving affected hash handling; exploitation can leak stack data, corrupt directory indexes, remount storage read-only, or panic the kernel.

CVSS severity7.8
High
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

Unchecked return handling in affected Linux kernel ext4 versions allows local users to disclose kernel memory and corrupt directories. Several ext4 name-lookup and directory-index callers ignore ext4fs_dirhash() errors and continue with zeroed or stale hash fields. The path requires local filesystem operations involving affected hash handling; exploitation can leak stack data, corrupt directory indexes, remount storage read-only, or panic the kernel.

The record

CVE
CVE-2023-53473
Published
Oct 1, 2025
Updated
Oct 1, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1005
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 1, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 1, 2025Record 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 <4b3cb1d108bfc2aebb0d7c8a52261a53cf7f5786
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <70d579aefa652a06af97e013e3fbbabbe5a43553
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b2531936118deb3f479c4fa1bcd787b74b8faa6a
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c1fae027da61fe8e7eb99f7244297e81bc0f1e43
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f68876aeef96ef8b708ab10b9cb47ce0a5adb424

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4b3cb1d108bfc2aebb0d7c8a52261a53cf7f5786; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <70d579aefa652a06af97e013e3fbbabbe5a43553; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b2531936118deb3f479c4fa1bcd787b74b8faa6a; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c1fae027da61fe8e7eb99f7244297e81bc0f1e43; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f68876aeef96ef8b708ab10b9cb47ce0a5adb424

Published CVSS scores

7.8Linux Kernel CVE TeamCVSS: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.

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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 exploitPublished

Weakness, pattern, technique

T1005Data from Local System

Public exploit references

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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