Amazon Linux 2 : rsyslog (ALAS-2026-3967)

high Nessus Plugin ID 365273

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Synopsis

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

Description

The version of rsyslog installed on the remote host is prior to 8.24.0-57. It is, therefore, affected by a vulnerability as referenced in the ALAS2-2026-3967 advisory.

rsyslog's omfile dynaFile facility intentionally allows templates to generate flexible output paths. This supports valid deployments that route logs into different directories or use dynamically generated file names.

A deployment becomes unsafe when a dynaFile template uses a value influenced by untrusted input as a path component without explicit secure-path handling. In that configuration, the rendered path can escape the operator's intended log directory.

This is not limited to the RFC5424 HOSTNAME field. Any untrusted value that reaches a dynaFile path component can create the condition.

An attacker who can influence such a value may cause rsyslog to create or append to files outside the intended output directory, subject to rsyslog's effective privileges and host confinement.

The practical result depends on the deployment. Mandatory access controls, systemd sandboxing, filesystem permissions, the configured input modules, and the selected output template can all limit or prevent impact. A code-execution outcome requires additional, deployment-specific conditions and is not representative of default distribution configurations.

Default Debian and Ubuntu configurations do not enable a network input and a dynaFile action of this form.
The affected configuration must be explicitly deployed. (CVE-2026-92709)

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 rsyslog' or or 'yum update --advisory ALAS2-2026-3967' to update your system.

Plugin Details

Severity: High

ID: 365273

File Name: al2_ALAS-2026-3967.nasl

Version: 1.2

Type: Local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 10/12/2026

Updated: 10/23/2026

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: 58.51

CVSS v2

Risk Factor: High

Base Score: 7.6

Temporal Score: 5.6

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

CVSS Score Source: CVE-2026-92709

CVSS v3

Risk Factor: High

Base Score: 8.1

Temporal Score: 7.1

Vector: CVSS:3.0/AV:N/AC:H/PR:N/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:rsyslog-crypto, p-cpe:/a:amazon:linux:rsyslog-debuginfo, p-cpe:/a:amazon:linux:rsyslog-doc, p-cpe:/a:amazon:linux:rsyslog-elasticsearch, p-cpe:/a:amazon:linux:rsyslog-gnutls, p-cpe:/a:amazon:linux:rsyslog-gssapi, p-cpe:/a:amazon:linux:rsyslog-kafka, p-cpe:/a:amazon:linux:rsyslog-libdbi, p-cpe:/a:amazon:linux:rsyslog-mmaudit, p-cpe:/a:amazon:linux:rsyslog-mmjsonparse, p-cpe:/a:amazon:linux:rsyslog-mmkubernetes, p-cpe:/a:amazon:linux:rsyslog-mmnormalize, p-cpe:/a:amazon:linux:rsyslog-mmsnmptrapd, p-cpe:/a:amazon:linux:rsyslog-mysql, p-cpe:/a:amazon:linux:rsyslog-pgsql, p-cpe:/a:amazon:linux:rsyslog-relp, p-cpe:/a:amazon:linux:rsyslog-snmp, p-cpe:/a:amazon:linux:rsyslog-udpspoof, p-cpe:/a:amazon:linux:rsyslog

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: 10/12/2026

Reference Information

CVE: CVE-2026-92709

Detections

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