CVE-2024-26638

Local service interruption via uninitialized NBD message field

Published Mar 18, 2024 · Updated May 11, 2026

Uninitialized memory use in the Linux NBD driver allows local users with high privileges to interrupt network block device operation. In __sock_xmit, a stack-allocated struct msghdr is not zero-initialized before sock_recvmsg passes it to tcp_recvmsg, leaving msg_get_inq undefined. Reachability requires privileged local control of an active NBD connection; published impact is limited to availability, with no reported data disclosure or modification.

CVSS severity4.4
Medium
EPSS probability0.22%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uninitialized memory use in the Linux NBD driver allows local users with high privileges to interrupt network block device operation. In __sock_xmit, a stack-allocated struct msghdr is not zero-initialized before sock_recvmsg passes it to tcp_recvmsg, leaving msg_get_inq undefined. Reachability requires privileged local control of an active NBD connection; published impact is limited to availability, with no reported data disclosure or modification.

The record

CVE
CVE-2024-26638
Published
Mar 18, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Mar 18, 2024CVE 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=5.19
  2. Affected versionversion=f94fd25cb0aaf77fd7453f31c5d394a1a68ecf60 <1960f2b534da1e6c65fb96f9e98bda773495f406
  3. Affected versionversion=f94fd25cb0aaf77fd7453f31c5d394a1a68ecf60 <78fbb92af27d0982634116c7a31065f24d092826
  4. Affected versionversion=f94fd25cb0aaf77fd7453f31c5d394a1a68ecf60 <b0028f333420a65a53a63978522db680b37379dd
  5. Affected versionversion=f94fd25cb0aaf77fd7453f31c5d394a1a68ecf60 <d9c54763e5cdbbd3f81868597fe8aca3c96e6387

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=5.19; version=f94fd25cb0aaf77fd7453f31c5d394a1a68ecf60 <1960f2b534da1e6c65fb96f9e98bda773495f406; version=f94fd25cb0aaf77fd7453f31c5d394a1a68ecf60 <78fbb92af27d0982634116c7a31065f24d092826; version=f94fd25cb0aaf77fd7453f31c5d394a1a68ecf60 <b0028f333420a65a53a63978522db680b37379dd; version=f94fd25cb0aaf77fd7453f31c5d394a1a68ecf60 <d9c54763e5cdbbd3f81868597fe8aca3c96e6387

Published CVSS scores

4.4CISA-ADPCVSS:3.1/AV:L/AC:L/PR:H/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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

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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