Amazon Linux 2 : samba, --advisory ALAS2-2026-3886 (ALAS-2026-3886)

high Nessus Plugin ID 341891

Synopsis

The remote Amazon Linux 2 host is missing a security update.

Description

The version of samba installed on the remote host is prior to 4.10.16-24. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2026-3886 advisory.

A flaw was found in samba's pam_winbind. When mkhomedir is enabled, pam_winbind chowns the target account's home directory without validating the path is not a critical system directory such as /. On affected systems, accounts with / as their home directory (a common default for system accounts) can have this triggered not only by root, but by a non-root user holding a narrow sudo delegation to run commands as that account, causing ownership of / to change and resulting in severe denial of service (SSH, sudo, and package-manager failures). The change does not grant write access to / (which ships with restrictive 0555 permissions on RHEL), so the impact is availability loss rather than further privilege escalation.
(CVE-2026-15779)

Samba AD LDAP Compare filter injection and trusted-request confusion disclose protected attributes (CVE-2026-58222)

The CTDB protocol has bounds checking issues

NOTE: https://www.samba.org/samba/security/CVE-2026-58224-advisory.html (CVE-2026-58224)

TSIG packet with name compression can crash DNS (CVE-2026-6949)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Run 'yum update samba' or or 'yum update --advisory ALAS2-2026-3886' to update your system.

Plugin Details

Severity: High

ID: 341891

File Name: al2_ALAS-2026-3886.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 8/31/2026

Updated: 8/31/2026

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Nessus Agent, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.14

CVSS v2

Risk Factor: High

Base Score: 9

Temporal Score: 6.7

Vector: CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:C

CVSS Score Source: CVE-2026-58222

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.7

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:ctdb-tests, p-cpe:/a:amazon:linux:ctdb, p-cpe:/a:amazon:linux:libsmbclient-devel, p-cpe:/a:amazon:linux:libsmbclient, p-cpe:/a:amazon:linux:libwbclient-devel, p-cpe:/a:amazon:linux:libwbclient, p-cpe:/a:amazon:linux:samba-client-libs, p-cpe:/a:amazon:linux:samba-client, p-cpe:/a:amazon:linux:samba-common-libs, p-cpe:/a:amazon:linux:samba-common-tools, p-cpe:/a:amazon:linux:samba-common, p-cpe:/a:amazon:linux:samba-dc-libs, p-cpe:/a:amazon:linux:samba-dc, p-cpe:/a:amazon:linux:samba-debuginfo, p-cpe:/a:amazon:linux:samba-devel, p-cpe:/a:amazon:linux:samba-krb5-printing, p-cpe:/a:amazon:linux:samba-libs, p-cpe:/a:amazon:linux:samba-pidl, p-cpe:/a:amazon:linux:samba-python-test, p-cpe:/a:amazon:linux:samba-python, p-cpe:/a:amazon:linux:samba-test-libs, p-cpe:/a:amazon:linux:samba-test, p-cpe:/a:amazon:linux:samba-vfs-glusterfs, p-cpe:/a:amazon:linux:samba-winbind-clients, p-cpe:/a:amazon:linux:samba-winbind-krb5-locator, p-cpe:/a:amazon:linux:samba-winbind-modules, p-cpe:/a:amazon:linux:samba-winbind, p-cpe:/a:amazon:linux:samba

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 8/31/2026

Vulnerability Publication Date: 7/15/2026

Reference Information

CVE: CVE-2026-15779, CVE-2026-58222, CVE-2026-58224, CVE-2026-6949

IAVA: 2026-A-0794

Detections

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