CVE-2025-38066

Host crash via repeated failed cache resume

Published Jun 18, 2025 · Updated May 11, 2026

Reachable assertion in affected Linux kernel releases allows local users to crash the host by retrying a failed dm-cache device resume. The device-mapper cache resume path permits another resume after corrupted mapping metadata leaves the SMQ policy object partly initialized, causing smq_load_mapping to reach BUG_ON while reloading mappings. Triggering the fault requires local access sufficient to alter cache metadata and resume the device twice; the resulting kernel oops interrupts the host.

CVSS severity5.5
Medium
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reachable assertion in affected Linux kernel releases allows local users to crash the host by retrying a failed dm-cache device resume. The device-mapper cache resume path permits another resume after corrupted mapping metadata leaves the SMQ policy object partly initialized, causing smq_load_mapping to reach BUG_ON while reloading mappings. Triggering the fault requires local access sufficient to alter cache metadata and resume the device twice; the resulting kernel oops interrupts the host.

The record

CVE
CVE-2025-38066
Published
Jun 18, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-617, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.2
  2. Affected versionversion=66a636356647a9be8885c2ce2948de126577698a <00586b78eeb7c626a14ca13453a1631f88a7cf36
  3. Affected versionversion=66a636356647a9be8885c2ce2948de126577698a <025c8f477625eb39006ded650e7d027bcfb20e79
  4. Affected versionversion=66a636356647a9be8885c2ce2948de126577698a <3986ef4a9b6a0d9c28bc325d8713beba5e67586f
  5. Affected versionversion=66a636356647a9be8885c2ce2948de126577698a <5da692e2262b8f81993baa9592f57d12c2703dea
  6. Affected versionversion=66a636356647a9be8885c2ce2948de126577698a <c5356a5e80442131e2714d0d26bb110590e4e568
  7. Affected versionversion=66a636356647a9be8885c2ce2948de126577698a <c614584c2a66b538f469089ac089457a34590c14
  8. Affected versionversion=66a636356647a9be8885c2ce2948de126577698a <cc80a5cc520939d0a7d071cc4ae4b3c55ef171d0
  9. Affected versionversion=66a636356647a9be8885c2ce2948de126577698a <f3128e3074e8af565cc6a66fe3384a56df87f803

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.2; version=66a636356647a9be8885c2ce2948de126577698a <00586b78eeb7c626a14ca13453a1631f88a7cf36; version=66a636356647a9be8885c2ce2948de126577698a <025c8f477625eb39006ded650e7d027bcfb20e79; version=66a636356647a9be8885c2ce2948de126577698a <3986ef4a9b6a0d9c28bc325d8713beba5e67586f; version=66a636356647a9be8885c2ce2948de126577698a <5da692e2262b8f81993baa9592f57d12c2703dea; version=66a636356647a9be8885c2ce2948de126577698a <c5356a5e80442131e2714d0d26bb110590e4e568; version=66a636356647a9be8885c2ce2948de126577698a <c614584c2a66b538f469089ac089457a34590c14; version=66a636356647a9be8885c2ce2948de126577698a <cc80a5cc520939d0a7d071cc4ae4b3c55ef171d0; version=66a636356647a9be8885c2ce2948de126577698a <f3128e3074e8af565cc6a66fe3384a56df87f803

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

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

CWE-617Reachable Assertion
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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