--- id: "CVE-2026-115419" kind: "vulnerability" aliases: ["CVE-2026-115419", "GHSA-4v6f-7vjh-6x4m"] title: "Strands Agents SDK: Exposure of data element to wrong session in the A2A Server" severity: "high" cvss: 8.6 epss: null exploited: false status: "open" category: "ai-tooling" products: [{"name": "strands-agents", "fixed": ["1.43.0"], "affected": "< 1.43.0", "ecosystem": "pypi"}, {"name": "@strands-agents/sdk", "fixed": ["1.5.0"], "affected": "< 1.5.0", "ecosystem": "npm"}] ecosystems: ["npm", "pypi"] tags: ["a2a", "ai-tooling", "aws", "cwe-488", "lab-disclosure", "multi-tenant", "python", "strands-agents", "typescript"] not_affected_if: ["patched-version", "single-user-deployment"] published_at: "2026-10-22T00:00:00+00:00" first_seen_at: "2026-10-23T20:59:05+00:00" updated_at: "2026-10-24T18:43:45+00:00" sources: [{"source": "ghsa", "url": "https://github.com/advisories/GHSA-4v6f-7vjh-6x4m", "first_seen_at": "2026-10-23T20:59:05+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-115419", "first_seen_at": "2026-10-23T21:57:32+00:00"}, {"source": "lab", "url": "https://aws.amazon.com/security/security-bulletins/rss/2026-146-aws/", "first_seen_at": "2026-10-24T18:43:45+00:00"}, {"source": "lab", "url": "https://aws.amazon.com/security/security-bulletins/rss/2026-146-aws/", "first_seen_at": "2026-10-24T18:43:45+00:00"}] --- # Strands Agents SDK: Exposure of data element to wrong session in the A2A Server The Strands Agents SDK's Agent2Agent (A2A) server in Python and TypeScript shares conversation history across callers that use different context_id values. An authenticated remote caller can read another caller's conversation history or influence model behavior for other callers. _Summary, check and fix written by a model from the sources; labelled as such._ ## Affected - pypi:strands-agents affected < 1.43.0 fixed 1.43.0 - npm:@strands-agents/sdk affected < 1.5.0 fixed 1.5.0 ## How to check Check whether strands-agents (Python) is below 1.43.0 or @strands-agents/sdk (TypeScript) is below 1.5.0 in your lockfiles, e.g. pip show strands-agents or npm ls @strands-agents/sdk. ## Fix Upgrade strands-agents to 1.43.0 or @strands-agents/sdk to 1.5.0 or later, and patch any forked code. No workaround fully addresses it; until upgraded, run a separate A2A server instance per user or tenant. ## Mitigated for you by - Team (workaround): covers Isolation between callers by running one A2A server instance per user or tenant, so no instance serves more than one caller Limits: The document states there is no workaround that fully addresses this issue in affected versions; it does not describe other exposure paths Still: Do not expose an A2A server to more than one user or tenant until upgrading; if multiple callers need access, run a separate A2A server instance for each user or tenant https://aws.amazon.com/security/security-bulletins/rss/2026-146-aws/ ## Timeline - 2026-10-23T20:59:05+00:00 ghsa https://github.com/advisories/GHSA-4v6f-7vjh-6x4m - 2026-10-23T21:57:32+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-115419 - 2026-10-24T18:43:45+00:00 lab https://aws.amazon.com/security/security-bulletins/rss/2026-146-aws/ — AWS: CVE-2026-115419 - Unintended disclosure of data element to wrong session in Strands Agents SDK A2A Server - 2026-10-24T18:43:45+00:00 lab https://aws.amazon.com/security/security-bulletins/rss/2026-146-aws/ — AWS: CVE-2026-115419 - Unintended disclosure of data element to wrong session in Strands Agents SDK A2A Server ## Documents - [advisory] AWS: CVE-2026-115419 - Unintended disclosure of data element to wrong session in Strands Agents SDK A2A Server https://aws.amazon.com/security/security-bulletins/rss/2026-146-aws/ ## From the sources **Summary** Strands Agents SDK is an open-source SDK, available for Python (strands-agents) and TypeScript (@strands-agents/sdk), for building and running AI agents. An issue exists where, under certain circumstances, the Agent2Agent (A2A) server shares conversation history across callers with different context\_id values, allowing one caller to read and influence another caller's session. **Impact** The A2A server did not properly isolate conversation state between callers. In multi-tenant deployments, an authenticated remote user could access another caller's conversation history or influence model behavior for other callers (CWE-488: Unintended Disclosure of Data Element to Wrong Session). This affects any deployment where an A2A server is reachable by more than one user or tenant. **Impacted versions:** strands-agents (Python): all versions containing the multiagent.a2a module, < 1.43.0 @strands-agents/sdk (TypeScript): < 1.5.0 **Patches** This issue has been addressed in strands-agents version 1.43.0 and @strands-agents/sdk version 1.5.0. The A2A server now uses an agent factory so conversation state is 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** If you have any questions or comments about this advisory, we ask that you contact AWS Security via our [vulnerability reporting page](https://aws.amazon.com/security/vulnerability-reporting) or directly via email to [aws-security@amazon.com](mailto:aws-security@amazon.com). Please do not create a public GitHub issue. --- _Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_