SB20260727135 - Out-of-bounds write in Linux kernel ntfs3



SB20260727135 - Out-of-bounds write in Linux kernel ntfs3

Published: July 27, 2026

Security Bulletin ID SB20260727135
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Code execution

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Out-of-bounds write (CVE-ID: CVE-2026-64432)

CWE-ID: CWE-787 - Out-of-bounds write

CVSSv4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a local user to cause a denial of service or execute arbitrary code.

The vulnerability exists due to an out-of-bounds write in log_replay in fs/ntfs3/fslog.c when mounting a crafted NTFS image and replaying the $LogFile journal. A local user can provide a specially crafted NTFS image to cause a denial of service or execute arbitrary code.

The issue can be triggered at mount time during the analysis pass when LCNs from an action log record are copied into an existing Dirty Page Table entry, and integer underflow in the target VCN delta can drive the destination index past the allocated page_lcns array.


Remediation

Install update from vendor's website.