Detections
Analytics
Amazon Linux 2 : amazon-ssm-agent (ALAS-2026-3350)
high Nessus Plugin ID 319796
Language:
Synopsis
The remote Amazon Linux 2 host is missing a security update.Description
The version of amazon-ssm-agent installed on the remote host is prior to 3.3.4515.0-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2026-3350 advisory.When processing HTTP/2 SETTINGS frames, transport will enter an infinite loop of writing CONTINUATION frames if it receives a SETTINGS_MAX_FRAME_SIZE with a value of 0. (CVE-2026-33814)
Improper limitation of a pathname to a restricted directory in the aws:downloadContent plugin in amazon- ssm-agent before 3.3.4515.0 might allow an authenticated remote user whose ssm:SendCommand permission is restricted to the AWS-DownloadContent document, to write arbitrary files outside the intended download directory with root privileges, via crafted object keys in the S3 source the document is directed to retrieve. This issue may lead to arbitrary code execution as root if specific sensitive files are overwritten.
To remediate this issue, customers should upgrade amazon-ssm-agent to version 3.3.4515.0 or later.
(CVE-2026-81849)
Tenable has extracted the preceding description block directly from the tested product security advisory.
Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.
Solution
Run 'yum update amazon-ssm-agent' or or 'yum update --advisory ALAS2-2026-3350' to update your system.See Also
https://alas.aws.amazon.com//AL2/ALAS2-2026-3350.html
https://alas.aws.amazon.com/faqs.html
Plugin Details
Severity: High
ID: 319796
File Name: al2_ALAS-2026-3350.nasl
Version: 1.2
Type: Local
Agent: unix
Published: 6/8/2026
Updated: 10/15/2026
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: 58.21
CVSS v2
Risk Factor: High
Base Score: 7.8
Temporal Score: 5.8
Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C
CVSS Score Source: CVE-2026-33814
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
CVSS v4
Risk Factor: High
Base Score: 8.7
Threat Score: 6.3
Threat Vector: CVSS:4.0/E:U
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS Score Source: CVE-2026-81849
Vulnerability Information
CPE: cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:amazon-ssm-agent
Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list
Exploit Ease: No known exploits are available
Patch Publication Date: 6/8/2026
Vulnerability Publication Date: 5/7/2026
Reference Information
CVE: CVE-2026-33814, CVE-2026-81849
IAVB: 2026-B-0120