Detections
Analytics

Amazon Linux 2 : rsyslog (ALAS-2026-3904)

high Nessus Plugin ID 345773

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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 ALAS2-2026-3904 advisory.

 A flaw was found in rsyslog. An unauthenticated remote attacker can trigger a heap buffer overflow in the RainerScript `replace()` function by sending specially crafted syslog messages. This vulnerability arises from an incorrect buffer size calculation during string replacement, causing memory corruption. Successful exploitation can lead to a denial of service (DoS) for the affected system. (CVE-2026-78002)

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 ALAS2-2026-3904' to update your system.

See Also

https://alas.aws.amazon.com//AL2/ALAS2-2026-3904.html

https://alas.aws.amazon.com/faqs.html

https://explore.alas.aws.amazon.com/CVE-2026-78002.html

Plugin Details

Severity: High

ID: 345773

File Name: al2_ALAS-2026-3904.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 9/14/2026

Updated: 9/14/2026

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: 23.66

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

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

CVSS Score Source: CVE-2026-78002

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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: 9/14/2026

Vulnerability Publication Date: 8/27/2026

Reference Information

CVE: CVE-2026-78002