CVE-2023-32258Network attack vector

Unauthenticated kernel code execution via session use-after-free

Published Jul 24, 2023 · Updated Mar 5, 2025

Use-after-free in Linux kernel ksmbd allows remote attackers to execute kernel code via concurrent SMB2 logoff and close requests. On multichannel sessions, SMB2_LOGOFF frees the tree connection while a concurrent SMB2_CLOSE still uses it because logoff waits only for requests on its own connection. Exploitation requires ksmbd and SMB multichannel to be enabled and a high-complexity race; success grants kernel-context code execution or crashes the system.

CVSS severity8.1
High
EPSS probability2.51%
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 kernel ksmbd allows remote attackers to execute kernel code via concurrent SMB2 logoff and close requests. On multichannel sessions, SMB2_LOGOFF frees the tree connection while a concurrent SMB2_CLOSE still uses it because logoff waits only for requests on its own connection. Exploitation requires ksmbd and SMB multichannel to be enabled and a high-complexity race; success grants kernel-context code execution or crashes the system.

The record

CVE
CVE-2023-32258
Published
Jul 24, 2023
Updated
Mar 5, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-667, CWE-362, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 24, 2023CVE publishedPublication date reported by the CVE source.
  2. Mar 5, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.1Red HatCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
8.1NVDCVSS:3.1/AV:N/AC:H/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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

CWE-667Improper Locking
CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
T1190Exploit Public-Facing Application

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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