---
id: CVE-2023-39176
title: >-
  A flaw was found within the parsing of SMB2 requests that have a transform
  header in the kernel ksmbd module
summary: >-
  A flaw was found within the parsing of SMB2 requests that have a transform
  header in the kernel ksmbd module. The issue results from the lack of proper
  validation of user-supplied data, which can result in a read past the end of
  an alloc…
severity: medium
cvss: 5.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N'
cwe:
  - CWE-125
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 5.15.121, < 5.15.127'
  - 'linux_kernel >= 6.1.36, < 6.1.46'
  - 'linux_kernel >= 6.3, < 6.3.10'
  - 'linux_kernel >= 6.4, < 6.4.11'
patched:
  - linux_kernel 6.4.11
published: '2024-11-18'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T19:15:14.353'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2023-39176'
references:
  - url: 'https://access.redhat.com/security/cve/CVE-2023-39176'
    label: patrick@puiterwijk.org
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2326503'
    label: patrick@puiterwijk.org
  - url: 'https://www.zerodayinitiative.com/advisories/ZDI-24-586/'
    label: patrick@puiterwijk.org
tags:
  - nvd
epss: 0.00672
epssPercentile: 0.50563
zeroDay: true
ingestedAt: '2026-10-08T20:06:22.173Z'
---

## Overview

A flaw was found within the parsing of SMB2 requests that have a transform header in the kernel ksmbd module. The issue results from the lack of proper validation of user-supplied data, which can result in a read past the end of an allocated buffer. An attacker can leverage this to disclose sensitive information on affected installations of Linux. Only systems with ksmbd enabled are vulnerable to this CVE.

## Affected

- `linux_kernel >= 5.15.121, < 5.15.127`
- `linux_kernel >= 6.1.36, < 6.1.46`
- `linux_kernel >= 6.3, < 6.3.10`
- `linux_kernel >= 6.4, < 6.4.11`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.4.11`