---
id: CVE-2026-64391
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ksmbd: use opener credentials for ADS I/O

  Alternate data streams are stored as xattrs
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ksmbd: use opener credentials for ADS I/O

  Alternate data streams are stored as xattrs. Unlike regular file I/O,
  their read and write paths therefore call VFS xattr hel…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 5.15, < 6.12.96'
  - 'linux_kernel >= 6.13, < 6.18.39'
  - 'linux_kernel >= 6.19, < 7.1.4'
patched:
  - linux_kernel 7.1.4
published: '2026-07-25'
updated: '2026-09-04'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-64391'
references:
  - url: 'https://git.kernel.org/stable/c/2b4592cea214683de0f2ce6f8c22c097fb0ea1ab'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/52a56cf53ec834c44ac1b4d16d585f26613ee5ce'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/a8f5d39971bbad9340d49cd41b0e2da9452a649d'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/baa5e094886fffa7e6272edcb5e08be5ce28262c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00457
epssPercentile: 0.36932
ingestedAt: '2026-09-05T13:39:57.480Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: use opener credentials for ADS I/O

Alternate data streams are stored as xattrs. Unlike regular file I/O,
their read and write paths therefore call VFS xattr helpers which recheck
inode permissions and LSM policy using the current task credentials.

Run ADS I/O with the credentials captured when the SMB handle was opened.

## Affected

- `linux_kernel >= 5.15, < 6.12.96`
- `linux_kernel >= 6.13, < 6.18.39`
- `linux_kernel >= 6.19, < 7.1.4`

## Remediation

Upgrade past the affected range:

- `linux_kernel 7.1.4`