CVE-2026-18830: Aws Amazon Bedrock Agentcore Harness

High severity, CVSS 8.1. EPSS: 0.5% chance of exploitation in the next 30 days.

Insufficient input validation in Amazon Bedrock AgentCore harness might allow an authenticated remote user to execute configured tools bypassing model invocation and security controls via crafted content blocks in conversation messages. AWS has addressed this issue. No customer action is required.

Affected products

• Aws Amazon Bedrock Agentcore Harness: affected versions not specified

Published 2026-08-04. Last modified 2026-08-06.