Amazon Linux 2 : acl, --advisory ALAS2-2026-3831 (ALAS-2026-3831)

high Nessus Plugin ID 332055

Synopsis

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

Description

The version of acl installed on the remote host is prior to 2.2.51-14. It is, therefore, affected by a vulnerability as referenced in the ALAS2-2026-3831 advisory.

A flaw was found in the `acl` component, specifically within its `libacl` pathname-based functions. A local attacker could exploit this vulnerability by using a symbolic link to replace a pathname component.
This could allow the attacker to redirect access control list (ACL) read or write operations to arbitrary files or directories, leading to unauthorized manipulation of ACLs and ultimately local privilege escalation. (CVE-2026-54369)

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

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

Solution

Run 'yum update acl' or or 'yum update --advisory ALAS2-2026-3831' to update your system.

Plugin Details

Severity: High

ID: 332055

File Name: al2_ALAS-2026-3831.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 8/4/2026

Updated: 8/4/2026

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: 4.3

Percentile: 53.61

CVSS v2

Risk Factor: Medium

Base Score: 6.2

Temporal Score: 4.6

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

CVSS Score Source: CVE-2026-54369

CVSS v3

Risk Factor: High

Base Score: 7.1

Temporal Score: 6.2

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

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

CVSS v4

Risk Factor: High

Base Score: 8.4

Threat Score: 5.8

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

Vulnerability Information

CPE: cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:acl-debuginfo, p-cpe:/a:amazon:linux:acl, p-cpe:/a:amazon:linux:libacl-devel, p-cpe:/a:amazon:linux:libacl

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

Exploit Ease: No known exploits are available

Patch Publication Date: 8/4/2026

Vulnerability Publication Date: 6/29/2026

Reference Information

CVE: CVE-2026-54369

Detections

Analytics