SB2026072746 - Always-Incorrect Control Flow Implementation in Linux kernel fs

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Main Vulnerability Database SB2026072746

SB2026072746 - Always-Incorrect Control Flow Implementation in Linux kernel fs

Published: July 27, 2026

Security Bulletin ID SB2026072746
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) Always-Incorrect Control Flow Implementation (CVE-ID: CVE-2026-64514)

CWE-ID: CWE-670 - Always-Incorrect Control Flow Implementation

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to improper handling of non-present page table entries in userfaultfd_must_wait() and userfaultfd_huge_must_wait() when checking writability during userfaultfd write-protect fault handling. A local user can trigger a fault involving a swap or migration entry to cause a denial of service.

In the worst case, the affected thread may remain asleep waiting for a wake event that never arrives.


Remediation

Install update from vendor's website.

References