SB2026080760 - NULL pointer dereference in Linux kernel btrfs

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Main Vulnerability Database SB2026080760

SB2026080760 - NULL pointer dereference in Linux kernel btrfs

Published: August 7, 2026

Security Bulletin ID SB2026080760
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) NULL pointer dereference (CVE-ID: CVE-2026-64593)

CWE-ID: CWE-476 - NULL Pointer Dereference

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 a NULL pointer dereference in btrfs_trim_free_extents in the Btrfs filesystem when processing a FITRIM ioctl on a rescanned device that is not writeable. A local user can issue a trim request to trigger a kernel crash and cause a denial of service.

The issue occurs when a previously missing device is rescanned, clearing the missing-device state while the block device pointer remains NULL.


Remediation

Install update from vendor's website.

References