CVE-2025-38443

Kernel crash via NBD configuration use-after-free

Published Jul 25, 2025 · Updated May 11, 2026

Use-after-free in the Linux kernel NBD driver allows local users with CAP_SYS_ADMIN to crash the kernel via a failed device connect. nbd_genl_connect starts the device before backend-file creation; on a later error it releases nbd->config while recv_work still uses it. Exploitation requires CAP_SYS_ADMIN in the initial user namespace and can interrupt the host through a kernel crash.

CVSS severity7.8
High
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the Linux kernel NBD driver allows local users with CAP_SYS_ADMIN to crash the kernel via a failed device connect. nbd_genl_connect starts the device before backend-file creation; on a later error it releases nbd->config while recv_work still uses it. Exploitation requires CAP_SYS_ADMIN in the initial user namespace and can interrupt the host through a kernel crash.

The record

CVE
CVE-2025-38443
Published
Jul 25, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416, T1499
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Jul 25, 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=5.14
  2. Affected versionversion=6497ef8df568afbf5f3e38825a4590ff41611a54 <002aca89753f666d878ca0eb8584c372684ac4ba
  3. Affected versionversion=6497ef8df568afbf5f3e38825a4590ff41611a54 <8586552df591e0a367eff44af0c586213eeecc3f
  4. Affected versionversion=6497ef8df568afbf5f3e38825a4590ff41611a54 <91fa560c73a8126868848ed6cd70607cbf8d87e2
  5. Affected versionversion=6497ef8df568afbf5f3e38825a4590ff41611a54 <aa9552438ebf015fc5f9f890dbfe39f0c53cf37e
  6. Affected versionversion=6497ef8df568afbf5f3e38825a4590ff41611a54 <cb121c47f364b51776c4db904a6a5a90ab0a7ec5
  7. Affected versionversion=6497ef8df568afbf5f3e38825a4590ff41611a54 <d46186eb7bbd9a11c145120f2d77effa8d4d44c2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=5.14; version=6497ef8df568afbf5f3e38825a4590ff41611a54 <002aca89753f666d878ca0eb8584c372684ac4ba; version=6497ef8df568afbf5f3e38825a4590ff41611a54 <8586552df591e0a367eff44af0c586213eeecc3f; version=6497ef8df568afbf5f3e38825a4590ff41611a54 <91fa560c73a8126868848ed6cd70607cbf8d87e2; version=6497ef8df568afbf5f3e38825a4590ff41611a54 <aa9552438ebf015fc5f9f890dbfe39f0c53cf37e; version=6497ef8df568afbf5f3e38825a4590ff41611a54 <cb121c47f364b51776c4db904a6a5a90ab0a7ec5; version=6497ef8df568afbf5f3e38825a4590ff41611a54 <d46186eb7bbd9a11c145120f2d77effa8d4d44c2

Published CVSS scores

7.8UbuntuCVSS: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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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