SB2026051282 - Multiple vulnerabilities in Samba



SB2026051282 - Multiple vulnerabilities in Samba

Published: May 12, 2026

Security Bulletin ID SB2026051282
CSH Severity
High
Patch available
YES
Number of vulnerabilities 3
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

High 33% Low 67%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 3 vulnerabilities.


1) Use-after-free (CVE-ID: N/A)

CWE-ID: CWE-416 - Use After Free

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear


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

The vulnerability exists due to use-after-free in CTDB read-only record handling when processing record operations. A remote user can trigger the flaw to cause a denial of service.

The advisory also mentions a resource leak bug in the same area.


2) Missing Release of Resource after Effective Lifetime (CVE-ID: N/A)

CWE-ID: CWE-772 - Missing Release of Resource after Effective Lifetime

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear


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

The vulnerability exists due to a file descriptor leak in vfs_glusterfs when handling directory operations over persistent SMB2 connections. A local user can maintain persistent SMB2 connections to cause a denial of service.

The issue results in unbounded memory growth on the GlusterFS brick.


3) Buffer overflow (CVE-ID: CVE-2026-40170)

CWE-ID: CWE-119 - Memory corruption

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber


The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to memory corruption in thirdparty ngtcp2 when processing network traffic. A remote attacker can send specially crafted network traffic to execute arbitrary code.


Remediation

Install update from vendor's website.