CVE-2026-106032 in Bedrock Agentcore Starter Toolkit
Summary
by MITRE • 10/07/2026
Server-side request forgery in the OpenAPI schema processing of the agent import functionality in Amazon Bedrock AgentCore Starter Toolkit before 0.3.14 might allow an authenticated remote actor in the same AWS account to cause the environment of a user importing a Bedrock Agent to issue arbitrary outbound requests and read arbitrary local files, via crafted external reference values in the OpenAPI content associated with a Bedrock Agent action group.
To remediate this issue, users should upgrade to version 0.3.14. Note that bedrock-agentcore-starter-toolkit is deprecated. The @aws/agentcore npm CLI is the supported replacement and does not contain this issue. Migration to @aws/agentcore is the recommended long-term path.
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Analysis
by VulDB Data Team • 10/07/2026
The vulnerability identified in Amazon Bedrock AgentCore Starter Toolkit prior to version 0.3.14 represents a critical server-side request forgery flaw embedded within the OpenAPI schema processing logic of the agent import functionality. This security defect allows an authenticated remote actor operating within the same AWS account to exploit the system by crafting malicious external reference values in the OpenAPI content associated with a Bedrock Agent action group. The core technical failure lies in the insufficient validation and sanitization of these references during the parsing phase, which permits the application to resolve URIs that are not strictly confined to expected internal or public endpoints. Consequently, this lack of restriction enables the environment hosting the user importing the Bedrock Agent to issue arbitrary outbound network requests. This capability effectively bypasses standard egress controls because the request originates from a trusted service context rather than an external attacker directly targeting infrastructure boundaries.
Beyond the ability to initiate unauthorized outbound traffic, the vulnerability extends to local file system access through techniques that leverage server-side request forgery patterns often associated with path traversal or internal protocol exploitation. By manipulating the OpenAPI schema references, an adversary can force the underlying runtime environment to read arbitrary files from the host machine where the agent is being processed. This exposure poses a severe risk as it may lead to the disclosure of sensitive configuration data, credentials stored in local files, or other proprietary information residing on the server. The impact is particularly acute because the exploitation requires only authenticated access within the same AWS account, lowering the barrier for attack significantly compared to vulnerabilities requiring external network access or unauthenticated entry points.
From a classification perspective, this vulnerability aligns with CWE-918 Server-Side Request Forgery and potentially CWE-20 Improper Input Validation regarding the handling of external references in OpenAPI specifications. In terms of offensive security frameworks such as MITRE ATT&CK, this behavior corresponds to techniques involving T1563 Remote Service Session Hijacking or more specifically data exfiltration via internal network probes if used for lateral movement, though primarily it facilitates information discovery and collection through local file access. The attack vector is classified as remote with authentication required, placing it within the context of account manipulation where an insider threat or a compromised service principal can escalate privileges by abusing trusted relationships between services.
To remediate this issue immediately, users must upgrade to version 0.3.14 of the Amazon Bedrock AgentCore Starter Toolkit which contains patches for the OpenAPI schema processing logic that restricts allowed external references and validates input more rigorously. However, it is crucial to note that the bedrock-agentcore-starter-toolkit package has been officially deprecated by AWS. The recommended long-term mitigation strategy involves migrating fully to @aws/agentcore npm CLI which serves as the supported replacement and does not contain this vulnerability. This migration ensures compliance with current security standards and provides access to ongoing support and updates, thereby eliminating the risk associated with legacy code paths that may harbor similar or unpatched flaws in future versions of deprecated libraries.