SB20261023190 - NULL pointer dereference in Linux kernel fs

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Main Vulnerability Database SB20261023190

SB20261023190 - NULL pointer dereference in Linux kernel fs

Published: October 23, 2026

Security Bulletin ID SB20261023190
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-2026-98979)

CWE-ID: CWE-476 - NULL Pointer Dereference

CVSSv4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a local privileged user to cause a denial of service by triggering a kernel fault that blocks subsequent mount operations system-wide.

The vulnerability exists due to an invalid pointer dereference in the Linux kernel mount namespace handling code when attaching an automount beneath an internal mount whose namespace is represented by an error pointer. A local privileged user can access an automount through a descriptor obtained from a fanotify event on an overlay filesystem's lower layer to trigger a fault in count_mounts() while the namespace semaphore is held for writing, blocking subsequent mount operations.


Remediation

Install update from vendor's website.

References