What’s Vulnerable › Vulnerabilities

CVE-2026-115419: Unintended disclosure of data element to wrong session in Strands Agents SDK A2A Server

• Severity: high (CVSS 8.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-22 · updated 2026-10-30
• Weakness: CWE-488

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).

Affected products

• AWS strands-agents: before 1.43.0 — fixed in 1.43.0
• AWS strands-agents/sdk: before 1.5.0 — fixed in 1.5.0

How to fix

Upgrade to a fixed version: AWS strands-agents 1.43.0; AWS strands-agents/sdk 1.5.0. Check the vendor advisory for mitigations.

References

• https://aws.amazon.com/security/security-bulletins/2026-146-aws/
• https://github.com/strands-agents/harness-sdk/security/advisories/GHSA-4v6f-7vjh-6x4m
• https://pypi.org/project/strands-agents/1.43.0/
• https://www.npmjs.com/package/@strands-agents/sdk/v/1.5.0

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