SB20260727278 - Improper access control in Linux kernel mm

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Main Vulnerability Database SB20260727278

SB20260727278 - Improper access control in Linux kernel mm

Published: July 27, 2026

Security Bulletin ID SB20260727278
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) Improper access control (CVE-ID: CVE-2026-64294)

CWE-ID: CWE-284 - Improper Access Control

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


The vulnerability allows a local user to disclose sensitive information.

The vulnerability exists due to improper access control in the mincore() and madvise(MADV_PAGEOUT) ownership checks when handling files on idmapped mounts. A local user can access these interfaces on a crafted idmapped mount to disclose sensitive information.

The issue affects side-channel protection logic and occurs because ownership was checked against an idmap that ignored the file's mount idmap.


Remediation

Install update from vendor's website.

References