CVE-2023-53006Network attack vector

Kernel crash via stale SMB Direct pointer

Published Mar 27, 2025 · Updated Aug 5, 2026

Use-after-free in Linux CIFS SMB Direct allows remote attackers to crash the kernel by disconnecting a mounted RDMA share. smbd_destroy frees the smbd_connection object but leaves server->smbd_conn pointing to it, and smbd_reconnect later dereferences that stale pointer. Reachability requires an existing RDMA-mounted CIFS share and a malicious or compromised SMB Direct server that forces a disconnect; the resulting kernel oops interrupts the host.

CVSS severity9.8
Critical
EPSS probability0.53%
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 Linux CIFS SMB Direct allows remote attackers to crash the kernel by disconnecting a mounted RDMA share. smbd_destroy frees the smbd_connection object but leaves server->smbd_conn pointing to it, and smbd_reconnect later dereferences that stale pointer. Reachability requires an existing RDMA-mounted CIFS share and a malicious or compromised SMB Direct server that forces a disconnect; the resulting kernel oops interrupts the host.

The record

CVE
CVE-2023-53006
Published
Mar 27, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 27, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=4.16
  2. Affected versionversion=8ef130f9ec27973f7b49e20c5a3b9134ca33026c <4b83bc6f87eedab4599b0123e572a422689444be
  3. Affected versionversion=8ef130f9ec27973f7b49e20c5a3b9134ca33026c <5109607a4ece7cd8536172bf7549eb4dce1f3576
  4. Affected versionversion=8ef130f9ec27973f7b49e20c5a3b9134ca33026c <91be54849d5392050f5b847b42bd5e6221551ac8
  5. Affected versionversion=8ef130f9ec27973f7b49e20c5a3b9134ca33026c <a9640c0b268405f2540e8203a545e930ea88bb7d
  6. Affected versionversion=8ef130f9ec27973f7b49e20c5a3b9134ca33026c <b7ab9161cf5ddc42a288edf9d1a61f3bdffe17c7
  7. Affected versionversion=8ef130f9ec27973f7b49e20c5a3b9134ca33026c <e037baee16e0b9ace7e730888fcae9cec11daff2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.16; version=8ef130f9ec27973f7b49e20c5a3b9134ca33026c <4b83bc6f87eedab4599b0123e572a422689444be; version=8ef130f9ec27973f7b49e20c5a3b9134ca33026c <5109607a4ece7cd8536172bf7549eb4dce1f3576; version=8ef130f9ec27973f7b49e20c5a3b9134ca33026c <91be54849d5392050f5b847b42bd5e6221551ac8; version=8ef130f9ec27973f7b49e20c5a3b9134ca33026c <a9640c0b268405f2540e8203a545e930ea88bb7d; version=8ef130f9ec27973f7b49e20c5a3b9134ca33026c <b7ab9161cf5ddc42a288edf9d1a61f3bdffe17c7; version=8ef130f9ec27973f7b49e20c5a3b9134ca33026c <e037baee16e0b9ace7e730888fcae9cec11daff2

Published CVSS scores

9.8LinuxCVSS:3.1/AV:N/AC:L/PR:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

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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