CVE-2025-38263

Kernel crash via unchecked NULL cache entry

Published Jul 9, 2025 · Updated May 11, 2026

NULL pointer dereference in Linux bcache allows local users to crash the kernel when cache-set allocation fails during registration. The error path calls bch_cache_set_unregister before register_cache_set populates c->cache, and cache_set_flush dereferences the resulting NULL cache entry. Low-privileged local access and a bcache registration path encountering allocation failure are required; the bounded result is service interruption through a kernel crash.

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

NULL pointer dereference in Linux bcache allows local users to crash the kernel when cache-set allocation fails during registration. The error path calls bch_cache_set_unregister before register_cache_set populates c->cache, and cache_set_flush dereferences the resulting NULL cache entry. Low-privileged local access and a bcache registration path encountering allocation failure are required; the bounded result is service interruption through a kernel crash.

The record

CVE
CVE-2025-38263
Published
Jul 9, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 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=3.10
  2. Affected versionversion=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <1e46ed947ec658f89f1a910d880cd05e42d3763e
  3. Affected versionversion=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <1f25f2d3fa29325320c19a30abf787e0bd5fc91b
  4. Affected versionversion=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <3f9e128186c99a117e304f1dce6d0b9e50c63cd8
  5. Affected versionversion=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <553f560e0a74a7008ad9dba05c3fd05da296befb
  6. Affected versionversion=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <667c3f52373ff5354cb3543e27237eb7df7b2333
  7. Affected versionversion=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <c4f5e7e417034b05f5d2f5fa9a872db897da69bd
  8. Affected versionversion=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <d54681938b777488e5dfb781b566d16adad991de

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.10; version=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <1e46ed947ec658f89f1a910d880cd05e42d3763e; version=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <1f25f2d3fa29325320c19a30abf787e0bd5fc91b; version=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <3f9e128186c99a117e304f1dce6d0b9e50c63cd8; version=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <553f560e0a74a7008ad9dba05c3fd05da296befb; version=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <667c3f52373ff5354cb3543e27237eb7df7b2333; version=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <c4f5e7e417034b05f5d2f5fa9a872db897da69bd; version=cafe563591446cf80bfbc2fe3bc72a2e36cf1060 <d54681938b777488e5dfb781b566d16adad991de

Published CVSS scores

5.5UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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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