SB2026091927 - Use-after-free in Linux kernel block null_blk driver

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Main Vulnerability Database SB2026091927

SB2026091927 - Use-after-free in Linux kernel block null_blk driver

Published: September 19, 2026

Security Bulletin ID SB2026091927
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Information disclosure

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Use-after-free (CVE-ID: CVE-2026-90189)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 0 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a local user to trigger a use-after-free condition.

The vulnerability exists due to a use-after-free in the null_blk err_dev cleanup path when accessing a configfs item that remains reachable after cleanup. A local user can access the reachable configfs item to trigger a use-after-free condition.

Exploitation requires a racing user-created device to be added to the device list before module initialization enters error cleanup.


Remediation

Install update from vendor's website.

References