ZeroHour

Search: “aws”

659 stories

AWS Systems Manager Agent Vulnerability Allows Attackers to Bypass Port-Forwarding Restrictions

Critical SSRF flaw in AWS SSM Agent (CVE-2026-89049) lets authenticated users bypass link-local denylists and reach EC2 Instance Metadata Service for IAM credentials.

CVE-2026-89049 (Critical, CVSS v3.1 AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H) affects Amazon SSM Agent versions earlier than 3.3.4851.0, with the fix shipping in 3.3.4851.0. The remote-host port-forwarding feature's denylist for link-local addresses can be bypassed because equivalent address representations are not validated, enabling SSRF to restricted endpoints such as the EC2 Instance Metadata Service at 169.254.169.254. An attacker with authenticated AWS access and ssm:StartSession permission could retrieve instance profile IAM credentials and pivot to S3, Secrets Manager, Lambda, or other cloud resources depending on role permissions.