SB20260727260 - Out-of-bounds read in Linux kernel udf



SB20260727260 - Out-of-bounds read in Linux kernel udf

Published: July 27, 2026

Security Bulletin ID SB20260727260
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Denial of service

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Out-of-bounds read (CVE-ID: CVE-2026-64324)

CWE-ID: CWE-125 - Out-of-bounds read

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to an out-of-bounds read in udf_free_blocks() and block bitmap handling in fs/udf/balloc.c when processing crafted UDF filesystem block extents. A local user can supply a crafted filesystem and truncate a writable file on it to cause a denial of service.

On systems where active users can mount removable UDF media without administrative privileges, user interaction is not required beyond mounting the media and truncating a file.


Remediation

Install update from vendor's website.