Description
A server-side request forgery issue due to improper validation of equivalent address representations in the port forwarding to remote hosts functionality in Amazon AWS Systems Manager Agent (SSM Agent) before 3.3.4851.0 on all platforms might allow an authenticated remote user to bypass the remote destination denylist and reach link-local endpoints, potentially obtaining the temporary IAM role credentials of a managed instance and acting with that role's permissions from outside the instance, via a crafted destination host value that uses an alternate representation of a denied link-local address.



To remediate this issue, users should upgrade to version 3.3.4851.0 or later.
Published: 2026-09-10
Score: 8.5 High
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories

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History

Thu, 10 Sep 2026 18:45:00 +0000

Type Values Removed Values Added
Description A server-side request forgery issue due to improper validation of equivalent address representations in the port forwarding to remote hosts functionality in Amazon AWS Systems Manager Agent (SSM Agent) before 3.3.4851.0 on all platforms might allow an authenticated remote user to bypass the remote destination denylist and reach link-local endpoints, potentially obtaining the temporary IAM role credentials of a managed instance and acting with that role's permissions from outside the instance, via a crafted destination host value that uses an alternate representation of a denied link-local address. To remediate this issue, users should upgrade to version 3.3.4851.0 or later.
Title Server-side request forgery in the Session Manager port forwarding functionality in AWS Systems Manager Agent
First Time appeared Aws
Aws amazon Ssm Agent
Weaknesses CWE-1289
CWE-918
CPEs cpe:2.3:a:aws:amazon_ssm_agent:*:*:*:*:*:*:*:*
Vendors & Products Aws
Aws amazon Ssm Agent
References
Metrics cvssV3_1

{'score': 9.9, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H'}

cvssV4_0

{'score': 8.5, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:H/SA:H'}

Subscriptions

Aws Amazon Ssm Agent
cve-icon MITRE

Status: PUBLISHED

Assigner: AMZN

Published:

Updated: 2026-09-10T18:42:49.620Z

Reserved: 2026-09-10T16:58:08.584Z

Link: CVE-2026-89049

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses