SB2026050618 - Improper resource shutdown or release in Linux kernel ext4



SB2026050618 - Improper resource shutdown or release in Linux kernel ext4

Published: May 6, 2026

Security Bulletin ID SB2026050618
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) Improper resource shutdown or release (CVE-ID: CVE-2026-43065)

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

The vulnerability exists due to improper resource shutdown or release in ext4_mb_release() discard work handling when remounting an ext4 filesystem from discard to nodiscard and immediately unmounting it. A local user can mount the filesystem with discard, delete a large number of files, remount it with nodiscard, and immediately unmount it to cause a denial of service.

Exploitation requires a specific sequence of filesystem mount, remount, and unmount operations while queued discard work is still pending.


Remediation

Install update from vendor's website.