CVE-2026-89049: AWS Systems Manager Agent SSRF in Session Manager port forwarding

CVE-2026-89049 · Severity: critical · CVSS 9.9 · Published 2026-09-10

AWS Systems Manager Agent (SSM Agent) is software that runs on EC2 instances and on-premises servers, providing remote management capabilities including port forwarding. A server-side request forgery (SSRF) vulnerability in the port forwarding feature allows authenticated users with port-forwarding permissions to bypass security controls and access the instance's metadata service, potentially obtaining temporary AWS credentials that could be used to escalate privileges or access sensitive AWS resources.

Technologies: Amazon AWS. Vendors: Amazon.

Quick answers

Is CVE-2026-89049 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-89049 being exploited in the wild.
How severe is CVE-2026-89049?
Critical severity, with a CVSS score of 9.9, published 10 September 2026.
Which products and versions are affected?
Amazon Systems Manager Agent < 3.3.4851.0.
Is there a fix for CVE-2026-89049?
A patch was published on 2026-09-10: Patch released in version 3.3.4851.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-89049 attacked?
It is attacked over the network, in a hosted service.
Am I affected by CVE-2026-89049?
Check whether you run Amazon AWS or Amazon Systems Manager Agent at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

CVE-2026-89049 is a server-side request forgery (SSRF) vulnerability in AWS Systems Manager Agent's remote-host port forwarding functionality. The root cause is improper validation of equivalent address representations, allowing attackers to bypass the remote destination denylist. An authenticated user with Session Manager port-forwarding permissions can exploit this vulnerability by using alternative address formats (such as numeric or hexadecimal representations) to reach link-local endpoints, including the AWS EC2 instance metadata service (169.254.169.254). Successful exploitation enables retrieval of the managed instance's temporary IAM role credentials, allowing the attacker to assume that role's permissions from outside the instance. The vulnerability affects all versions of SSM Agent prior to 3.3.4851.0 that support remote-host port forwarding. Patches are available in version 3.3.4851.0 and later.

Affected products

  • AWS Systems Manager Agent < 3.3.4851.0

Timeline

  • 2026-09-10: disclosed
  • 2026-09-10: patched: Patch released in version 3.3.4851.0

References

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