---
id: CVE-2026-72318
title: 'cifs: validate DFS referral string offsets'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  cifs: validate DFS referral string offsets

  parse_dfs_referrals() validates that the response header and referral
  array fit in the received buffer, but each referral al…
severity: critical
cvss: 9.4
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 4ecce920e13ace16a5ba45efe8909946c28fb2ad <
    76c607b9353d377b1d1b11db50e743eee0ccf658
  - >-
    Linux >= 4ecce920e13ace16a5ba45efe8909946c28fb2ad <
    d64b6be5740ce230aca184d8d224c75d9866045d
  - >-
    Linux >= 4ecce920e13ace16a5ba45efe8909946c28fb2ad <
    929a85932d14190988f1eafd6ee8cc68d66ace0b
  - >-
    Linux >= 4ecce920e13ace16a5ba45efe8909946c28fb2ad <
    b784cd1c24d89bf71be2efe1e948ff7c03371e57
  - >-
    Linux >= 4ecce920e13ace16a5ba45efe8909946c28fb2ad <
    c37abc99bb3de3d3219ecef253d649f74117fd83
  - >-
    Linux >= 4ecce920e13ace16a5ba45efe8909946c28fb2ad <
    027a84ac6b50c12ef767c15abfc58aa865820e9e
  - Linux 4.11
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-16T18:46:37.626528Z'
published: '2026-08-15'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T18:55:17.318Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-72318'
references:
  - url: 'https://git.kernel.org/stable/c/76c607b9353d377b1d1b11db50e743eee0ccf658'
  - url: 'https://git.kernel.org/stable/c/d64b6be5740ce230aca184d8d224c75d9866045d'
  - url: 'https://git.kernel.org/stable/c/929a85932d14190988f1eafd6ee8cc68d66ace0b'
  - url: 'https://git.kernel.org/stable/c/b784cd1c24d89bf71be2efe1e948ff7c03371e57'
  - url: 'https://git.kernel.org/stable/c/c37abc99bb3de3d3219ecef253d649f74117fd83'
  - url: 'https://git.kernel.org/stable/c/027a84ac6b50c12ef767c15abfc58aa865820e9e'
tags:
  - cve.org
epss: 0.00586
epssPercentile: 0.4689
ingestedAt: '2026-10-16T19:46:24.409Z'
---

## Overview

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

cifs: validate DFS referral string offsets

parse_dfs_referrals() validates that the response header and referral
array fit in the received buffer, but each referral also contains string
offsets supplied by the server.

Those offsets are used to compute the DfsPath and NetworkAddress string
pointers without checking whether they still point inside the response
buffer. A malformed referral can therefore make the computed pointer
exceed the end of the buffer. The resulting negative max_len is then
passed to cifs_strndup_from_utf16(), and the non-Unicode path forwards it
to kstrndup() as a size_t, allowing strnlen() to read out of bounds.

Validate each string offset before deriving the string pointer.

## Affected

- `Linux >= 4ecce920e13ace16a5ba45efe8909946c28fb2ad < 76c607b9353d377b1d1b11db50e743eee0ccf658`
- `Linux >= 4ecce920e13ace16a5ba45efe8909946c28fb2ad < d64b6be5740ce230aca184d8d224c75d9866045d`
- `Linux >= 4ecce920e13ace16a5ba45efe8909946c28fb2ad < 929a85932d14190988f1eafd6ee8cc68d66ace0b`
- `Linux >= 4ecce920e13ace16a5ba45efe8909946c28fb2ad < b784cd1c24d89bf71be2efe1e948ff7c03371e57`
- `Linux >= 4ecce920e13ace16a5ba45efe8909946c28fb2ad < c37abc99bb3de3d3219ecef253d649f74117fd83`
- `Linux >= 4ecce920e13ace16a5ba45efe8909946c28fb2ad < 027a84ac6b50c12ef767c15abfc58aa865820e9e`
- `Linux 4.11`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.