SB20260727258 - Out-of-bounds write in Linux kernel udf



SB20260727258 - Out-of-bounds write in Linux kernel udf

Published: July 27, 2026

Security Bulletin ID SB20260727258
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-2026-64322)

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

CVSSv4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N]


The vulnerability allows a local user to disclose sensitive information and corrupt memory.

The vulnerability exists due to out-of-bounds read and out-of-bounds write in udf sparing table handling in fs/udf/super.c when parsing a crafted UDF image. A local user can mount or otherwise trigger processing of a specially crafted UDF image to disclose sensitive information and corrupt memory.

The issue is caused by validating reallocationTableLen as a byte count even though it is later used as an entry count for sparingEntry array access.


Remediation

Install update from vendor's website.