CVE-2023-53681

Kernel crash via uninitialized bcache node pointer

Published Oct 7, 2025 · Updated Oct 7, 2025

NULL pointer dereference in Linux bcache 3.10 through 6.4.3 allows local users to crash the kernel during a B-tree split. In drivers/md/bcache/btree.c, __bch_btree_node_alloc can return an uninitialized or NULL node pointer, which the btree_split call chain dereferences. Reachability requires local low-privileged access and an active bcache cache set undergoing a B-tree split; the bounded consequence is a kernel crash.

CVSS severity5.5
Medium
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in Linux bcache 3.10 through 6.4.3 allows local users to crash the kernel during a B-tree split. In drivers/md/bcache/btree.c, __bch_btree_node_alloc can return an uninitialized or NULL node pointer, which the btree_split call chain dereferences. Reachability requires local low-privileged access and an active bcache cache set undergoing a B-tree split; the bounded consequence is a kernel crash.

The record

CVE
CVE-2023-53681
Published
Oct 7, 2025
Updated
Oct 7, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 7, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 7, 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=3.10
  2. Affected versionversion=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <4514847aee18d9391a0cf3aad75d3567c72795a4
  3. Affected versionversion=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <587b4e8bb5dac682f09280ab35db4632b29d5ac4
  4. Affected versionversion=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <7ecea5ce3dc17339c280c75b58ac93d8c8620d9f
  5. Affected versionversion=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <80fca8a10b604afad6c14213fdfd816c4eda3ee4
  6. Affected versionversion=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <a4405f6ee03323410d7b10966fd67b35f71b1944
  7. Affected versionversion=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <b070f29a61436f6f8a2e3abc7ea4f4be81695198
  8. Affected versionversion=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <f67b0e3081f2a24170280a33ac66f6b112083c03

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.10; version=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <4514847aee18d9391a0cf3aad75d3567c72795a4; version=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <587b4e8bb5dac682f09280ab35db4632b29d5ac4; version=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <7ecea5ce3dc17339c280c75b58ac93d8c8620d9f; version=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <80fca8a10b604afad6c14213fdfd816c4eda3ee4; version=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <a4405f6ee03323410d7b10966fd67b35f71b1944; version=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <b070f29a61436f6f8a2e3abc7ea4f4be81695198; version=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <f67b0e3081f2a24170280a33ac66f6b112083c03

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

CWE-476NULL Pointer Dereference
T1499.004Application or System Exploitation

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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