What is CVE-2026-89049?

CVE-2026-89049 is a critical-severity vulnerability in AWS Amazon Ssm Agent, classified under Server-Side Request Forgery (SSRF). CVSS score: 9.9/10. Published 2026-09-10.

How severe is CVE-2026-89049?

Critical severity. CVSS v3 base score is 9.9 out of 10.

SSRF in AWS Amazon Ssm Agent

CVE-2026-89049

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.

Vulnerability class: SSRF (Server-Side Request Forgery)

CVSS v3 metric

CVSS v3 base score 9.9 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

Affected products

Aws Amazon Ssm Agent

Weakness classification (CWE)

References

ff89ba41-3aa1-4d27-914a-91399e9639e5 (patch)
ff89ba41-3aa1-4d27-914a-91399e9639e5 (vendor-advisory)
ff89ba41-3aa1-4d27-914a-91399e9639e5 (third-party-advisory)

Frequently asked questions

What is CVE-2026-89049?: CVE-2026-89049 is a critical-severity vulnerability in AWS Amazon Ssm Agent, classified under Server-Side Request Forgery (SSRF). CVSS score: 9.9/10. Published 2026-09-10.
How severe is CVE-2026-89049?: Critical severity. CVSS v3 base score is 9.9 out of 10.