SB20261023188 - Incorrect authorization in Linux kernel fs

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Main Vulnerability Database SB20261023188

SB20261023188 - Incorrect authorization in Linux kernel fs

Published: October 23, 2026

Security Bulletin ID SB20261023188
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Local access
Highest impact Data manipulation

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Incorrect authorization (CVE-ID: CVE-2026-98977)

CWE-ID: CWE-863 - Incorrect Authorization

CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N]


The vulnerability allows a local user to clear security flags on propagated automounts in their own namespace and prevent the host from changing flags on its own automounts.

The vulnerability exists due to incorrect authorization in the Linux kernel's attach_recursive_mnt() function in fs/namespace.c when assigning mount locks during automount propagation across user namespaces. A local user can trigger an automount through a directory descriptor referring to a host mount from a child namespace to cause the host's automount to be locked instead of the child's copy, allowing changes to mount security flags in the child namespace while blocking corresponding host operations.


Remediation

Install update from vendor's website.

References