Vulnerability · Published Oct 22, 2026 · Assigned by AMZN

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

High 8.1

In plain English

A high-severity security flaw in strands-agents from AWS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 37% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.1High

Exploit odds (30 days)0.4%top 63.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official 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 packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
PyPI	strands-agents	1.43.0	GHSA-4v6f-7vjh-6x4m
npm	@strands-agents/sdk	1.5.0	GHSA-4v6f-7vjh-6x4m

Affected products (as reported)

Vendor	Product	Versions
AWS	strands-agents	0 – before 1.43.0
AWS	strands-agents/sdk	0 – before 1.5.0

Weakness: CWE-488 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

References

https://pypi.org/project/strands-agents/1.43.0/ release-notes, patch
https://www.npmjs.com/package/@strands-agents/sdk/v/1.5.0 release-notes, patch
https://aws.amazon.com/security/security-bulletins/2026-146-aws/ vendor-advisory
https://github.com/strands-agents/harness-sdk/security/advisories/GHSA-4v6f-7vjh-6x4m third-party-advisory