Amazon Linux 2 : policycoreutils (ALAS-2026-3949)

medium Nessus Plugin ID 351023

Synopsis

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

Description

The version of policycoreutils installed on the remote host is prior to 2.5-22. It is, therefore, affected by a vulnerability as referenced in the ALAS2-2026-3949 advisory.

A TOCTOU (Time-of-Check-Time-of-Use) race condition vulnerability was found in the fixfiles script in policycoreutils. When running fixfiles relabel or fixfiles restore, the script used find and chcon commands to locate and relabel unlabeled files under /tmp and other directories. A local attacker could exploit a race window between the file discovery and the label change operation by swapping directory components with symlinks, causing chcon to follow the symlink and modify SELinux labels on arbitrary system files. This could undermine SELinux mandatory access control protections on critical files such as /etc/shadow. (CVE-2026-19079)

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 policycoreutils' or or 'yum update --advisory ALAS2-2026-3949' to update your system.

Plugin Details

Severity: Medium

ID: 351023

File Name: al2_ALAS-2026-3949.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 9/29/2026

Updated: 9/29/2026

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

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.76

CVSS v2

Risk Factor: Low

Base Score: 3.8

Temporal Score: 2.8

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

CVSS Score Source: CVE-2026-19079

CVSS v3

Risk Factor: Medium

Base Score: 4.4

Temporal Score: 3.9

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

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

Vulnerability Information

CPE: cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:policycoreutils-debuginfo, p-cpe:/a:amazon:linux:policycoreutils-devel, p-cpe:/a:amazon:linux:policycoreutils-gui, p-cpe:/a:amazon:linux:policycoreutils-newrole, p-cpe:/a:amazon:linux:policycoreutils-python, p-cpe:/a:amazon:linux:policycoreutils-restorecond, p-cpe:/a:amazon:linux:policycoreutils-sandbox, p-cpe:/a:amazon:linux:policycoreutils

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

Exploit Ease: No known exploits are available

Patch Publication Date: 9/28/2026

Vulnerability Publication Date: 8/7/2026

Reference Information

CVE: CVE-2026-19079

Detections

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