SB20260824247 - Improper access control in Linux kernel crypto



SB20260824247 - Improper access control in Linux kernel crypto

Published: August 24, 2026

Security Bulletin ID SB20260824247
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) Improper access control (CVE-ID: CVE-2026-74595)

CWE-ID: CWE-284 - Improper Access Control

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


The vulnerability allows a local user to bypass owner checks and set an encryption policy on a file.

The vulnerability exists due to improper access control in fscrypt_ioctl_set_policy() when handling ioctl requests on idmapped mounts. A local user can issue a crafted ioctl on an idmapped mount to bypass owner checks and set an encryption policy on a file.

The issue occurs because the check uses the unmapped on-disk owner rather than the mapped owner on mounts that support idmapping.


Remediation

Install update from vendor's website.