CVE-2025-38034Public exploit

Kernel crash via reversed btrfs reference arguments

Published Jun 18, 2025 · Updated May 11, 2026

NULL pointer dereference in btrfs in Linux 4.14 and later before branch-specific fixes allows local users to crash the kernel during writeback. btrfs_prelim_ref() passes old and new references in the wrong order, causing trace_btrfs_prelim_ref_insert() to dereference a NULL oldref pointer. Exploitation requires local access, permission to enable btrfs preliminary-reference tracing, and writeback activity; the observed consequence is a kernel oops that interrupts the system.

CVSS severity5.5
Medium
EPSS probability0.19%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in btrfs in Linux 4.14 and later before branch-specific fixes allows local users to crash the kernel during writeback. btrfs_prelim_ref() passes old and new references in the wrong order, causing trace_btrfs_prelim_ref_insert() to dereference a NULL oldref pointer. Exploitation requires local access, permission to enable btrfs preliminary-reference tracing, and writeback activity; the observed consequence is a kernel oops that interrupts the system.

The record

CVE
CVE-2025-38034
Published
Jun 18, 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. Jun 18, 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=00142756e1f8015d2f8ce96532d156689db7e448 <0528bba48dce7820d2da72e1a114e1c4552367eb
  2. Affected versionversion=00142756e1f8015d2f8ce96532d156689db7e448 <137bfa08c6441f324d00692d1e9d22cfd773329b
  3. Affected versionversion=00142756e1f8015d2f8ce96532d156689db7e448 <5755b6731655e248c4f1d52a2e1b18795b4a2a3a
  4. Affected versionversion=00142756e1f8015d2f8ce96532d156689db7e448 <7a97f961a568a8f72472dc804af02a0f73152c5f
  5. Affected versionversion=00142756e1f8015d2f8ce96532d156689db7e448 <7f7c8c03feba5f2454792fab3bb8bd45bd6883f9
  6. Affected versionversion=00142756e1f8015d2f8ce96532d156689db7e448 <a641154cedf9d69730f8af5d0a901fe86e6486bd
  7. Affected versionversion=00142756e1f8015d2f8ce96532d156689db7e448 <a876703894a6dd6e8c04b0635d86e9f7a7c81b79
  8. Affected versionversion=00142756e1f8015d2f8ce96532d156689db7e448 <bc7e0975093567f51be8e1bdf4aa5900a3cf0b1e
  9. Affected versionversion=4.14

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=00142756e1f8015d2f8ce96532d156689db7e448 <0528bba48dce7820d2da72e1a114e1c4552367eb; version=00142756e1f8015d2f8ce96532d156689db7e448 <137bfa08c6441f324d00692d1e9d22cfd773329b; version=00142756e1f8015d2f8ce96532d156689db7e448 <5755b6731655e248c4f1d52a2e1b18795b4a2a3a; version=00142756e1f8015d2f8ce96532d156689db7e448 <7a97f961a568a8f72472dc804af02a0f73152c5f; version=00142756e1f8015d2f8ce96532d156689db7e448 <7f7c8c03feba5f2454792fab3bb8bd45bd6883f9; version=00142756e1f8015d2f8ce96532d156689db7e448 <a641154cedf9d69730f8af5d0a901fe86e6486bd; version=00142756e1f8015d2f8ce96532d156689db7e448 <a876703894a6dd6e8c04b0635d86e9f7a7c81b79; version=00142756e1f8015d2f8ce96532d156689db7e448 <bc7e0975093567f51be8e1bdf4aa5900a3cf0b1e; version=4.14

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5Canonical UbuntuCVSS: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 11, 2026Sep 17, 2026
Latest reporting daySep 17, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

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

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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