CVE-2026-115419 - Unintended disclosure of data element to wrong session in Strands Agents SDK A2A Server
Bulletin ID: 2026-146-AWS
Scope: AWS
Content Type: Important (requires attention)
Publication Date: 10/22/2026 13:00 PM PDT
Description:
Strands Agents is an open-source SDK, available for Python and TypeScript, for building AI agents. The SDK includes an Agent2Agent (A2A) server component that exposes an agent over HTTP so other agents and clients can call it. We identified CVE-2026-115419, an issue where the A2A server did not properly isolate conversation state between callers. An authenticated remote user could access another caller's conversation history or influence model behavior for other callers in multi-tenant deployments.
Impacted versions:
- strands-agents (Python): all versions containing the multiagent.a2a module, < 1.43.0
- @strands-agents/sdk (TypeScript): < 1.5.0
Resolution:
This issue has been addressed in strands-agents version 1.43.0 and @strands-agents/sdk version 1.5.0. Conversation state is now isolated per A2A context_id. We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes..
Workarounds:
There is no workaround that fully addresses this issue in affected versions. Until you upgrade, do not expose an A2A server to more than one user or tenant. If multiple callers need access, run a separate A2A server instance for each user or tenant.
References:
Please email aws-security@amazon.com with any security questions or concerns.