CVE-2026-115419

High

Description

The A2A server component in Amazon Strands Agents SDK for Python before 1.43.0 and Amazon Strands Agents SDK for TypeScript before 1.5.0 does not properly isolate conversation state between callers. An authenticated remote user could read other tenants' conversation history and add persistent instructions that alter model behavior for subsequent callers via HTTP requests to the A2A endpoint using a different context_id. To mitigate this issue, users should upgrade to strands-agents 1.43.0 (Python) or @strands-agents/sdk 1.5.0 (TypeScript).

SeverityHigh

CVSS8.1

Exploit probability—

ProductStrands-agents

PublishedOct 22, 2026

First seenOct 22, 2026

Weakness typeCWE-488CWE-488

How to fix

Update

strands-agents1.43.0 or later
@strands-agents/sdk1.5.0 or later

Patches

Vendor advisories

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

Affected products

Product	Affected versions	Fixed in
strands-agentsPyPI	v < 1.43.0	1.43.0
@strands-agents/sdknpm	v < 1.5.0	1.5.0

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