CVE-2023-32257Network attack vector

Unauthenticated kernel code execution via session race

Published Jul 24, 2023 · Updated Jul 29, 2025

A race condition in Linux kernel ksmbd allows remote attackers to execute arbitrary code through concurrent SMB session requests. The SMB2 session setup path can restore a connection to KSMBD_SESS_GOOD while a concurrent logoff deletes the session because connection state and session lookup lack coordinated locking. Authentication is unnecessary, but ksmbd must be enabled; successful exploitation runs code in the kernel context.

CVSS severity8.1
High
EPSS probability2.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A race condition in Linux kernel ksmbd allows remote attackers to execute arbitrary code through concurrent SMB session requests. The SMB2 session setup path can restore a connection to KSMBD_SESS_GOOD while a concurrent logoff deletes the session because connection state and session lookup lack coordinated locking. Authentication is unnecessary, but ksmbd must be enabled; successful exploitation runs code in the kernel context.

The record

CVE
CVE-2023-32257
Published
Jul 24, 2023
Updated
Jul 29, 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. Jul 29, 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

8.1CanonicalCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
8.1Red Hat, Inc.CVSS: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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