Amazon Linux 2023 : sudo, sudo-devel, sudo-logsrvd (ALAS2023-2026-3156)

high Nessus Plugin ID 365184

Synopsis

The remote Amazon Linux 2023 host is missing a security update.

Description

It is, therefore, affected by a vulnerability as referenced in the ALAS2023-2026-3156 advisory.

A flaw was found in sudo. When sudoers rules use NOTBEFORE or NOTAFTER time-based access restrictions with timestamps that omit the trailing 'Z' timezone indicator, the time evaluation relies on the TZ environment variable inherited from the calling user. Because sudo is a setuid-root program, an unprivileged local user can set TZ to an extreme timezone offset to shift the authorization window by up to approximately 25 hours, causing expired rules to be treated as valid. This allows the user to execute commands outside the intended time window. Authentication is not bypassed; only the time-based authorization check is affected.
(CVE-2026-96512)

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 'dnf update sudo --releasever 2023.12.20261012' or or 'dnf update --advisory ALAS2023-2026-3156 --releasever 2023.12.20261012' to update your system.

Plugin Details

Severity: High

ID: 365184

File Name: al2023_ALAS2023-2026-3156.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 10/12/2026

Updated: 10/12/2026

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: Medium

Score: 4.9

Percentile: 58.41

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

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

CVSS Score Source: CVE-2026-96512

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

Vector: CVSS:3.0/AV:L/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:2023, p-cpe:/a:amazon:linux:sudo-debuginfo, p-cpe:/a:amazon:linux:sudo-debugsource, p-cpe:/a:amazon:linux:sudo-devel, p-cpe:/a:amazon:linux:sudo-logsrvd-debuginfo, p-cpe:/a:amazon:linux:sudo-logsrvd, p-cpe:/a:amazon:linux:sudo-python-plugin-debuginfo, p-cpe:/a:amazon:linux:sudo-python-plugin, p-cpe:/a:amazon:linux:sudo

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

Exploit Ease: No known exploits are available

Patch Publication Date: 10/12/2026

Vulnerability Publication Date: 9/23/2026

Reference Information

CVE: CVE-2026-96512

Detections

Analytics