Vulnerability feed

Executive summary

Amazon's Strands Agents SDK, available for Python and TypeScript, has a flaw in its Agent2Agent server component that can let one caller see another caller's conversation data. The advisory says an authenticated user could reach other callers' conversation history or influence model behavior in multi-tenant deployments. The vendor recommends upgrading to Python version 1.43.0 or TypeScript version 1.5.0 and has no full workaround for affected versions.

Technical summary

The A2A server did not properly isolate conversation state between callers, which is an improper isolation or cross-session data exposure issue. An authenticated remote user could access another caller's conversation history or influence model behavior for other callers in multi-tenant deployments. Affected versions are strands-agents (Python) versions containing the multiagent.a2a module before 1.43.0, and @strands-agents/sdk (TypeScript) before 1.5.0. Fixed versions are strands-agents 1.43.0 and @strands-agents/sdk 1.5.0, where conversation state is now isolated per A2A context_id. The advisory states there is no workaround that fully addresses the issue; until upgrade, it advises not exposing an A2A server to more than one user or tenant, or running a separate server instance per user or tenant. No detection guidance or exploitation status is stated in the advisory.

Summaries are generated by AI from the linked advisory text. Confirm versions and fixes at the source.

Summarized from aws.amazon.com/security/security-bulletins/2026-146-aws

Impact if exploited

How it is exploited

Attack vector

Network

Attack complexity

Low

Attack requirements

None

Privileges required

Low

User interaction

None

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affects

AWSAmazonAWS strands-agentsAWS strands-agents/sdkAmazon Strands Agents SDK for PythonAmazon Strands Agents SDK for TypeScriptAmazon Strands Agents SDK A2A Server