SB2026072091 - Memory leak in Linux kernel smb server

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Main Vulnerability Database SB2026072091

SB2026072091 - Memory leak in Linux kernel smb server

Published: July 20, 2026

Security Bulletin ID SB2026072091
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Memory leak (CVE-ID: CVE-2026-64139)

CWE-ID: CWE-401 - Missing release of memory after effective lifetime

CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to a memory leak in set_posix_acl_entries_dacl() in ksmbd when processing a malicious or malformed file with enough POSIX ACL entries to trigger the DACL size overflow check. A remote attacker can send or access a crafted file to cause a denial of service.

The issue occurs because cleanup is skipped when overflow handling breaks out of ACE-building loops.


Remediation

Install update from vendor's website.

References