SB2026080627 - Out-of-bounds read in Linux kernel btrfs



SB2026080627 - Out-of-bounds read in Linux kernel btrfs

Published: August 6, 2026

Security Bulletin ID SB2026080627
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-2026-64567)

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 io_ctl_check_crc() in the btrfs free space cache loader when loading a corrupted v1 free space cache. A local user can modify free space cache header counts to exceed the number of allocated pages to cause a denial of service.

The invalid out-of-bounds slot is treated as a struct page and can lead to a general protection fault during crc32c() processing.


Remediation

Install update from vendor's website.