high · 8.6 Patched

Strands Agents SDK: Exposure of data element to wrong session in the A2A Server

CVE-2026-115419 · GHSA-4v6f-7vjh-6x4m · published 23 Oct 2026

How serious is it

  • Severity: high, CVSS score 8.6 out of 10.
  • No exploit prediction (EPSS) score yet.
  • Not on the CISA list of exploited vulnerabilities.
  • No public exploit in Exploit-DB.

Is your app affected by CVE-2026-115419?

Paste this prompt into Claude Code, Cursor or any AI coding tool: it runs a free Shippable scan of your project and fixes what it finds. Built with Lovable, Bolt or v0? Scan your live app. Or upload your package file.

Who is affected

  • strands-agents (PyPI) < 1.43.0
  • @strands-agents/sdk (npm) < 1.5.0

How to check

  1. Run pip show strands-agents in your project to see the installed version, including copies pulled in by other packages.
  2. Run npm ls @strands-agents/sdk in your project to see the installed version, including copies pulled in by other packages.
  3. Or paste your lockfile into the checker: it lists every package with a known vulnerability, this one included.
  4. Or run npx shippable-dev scan localhost:3000 in your project folder. It reads your lockfile and flags this vulnerability along with every other known one.

How to fix

Copies a prompt for Claude Code, Cursor or Codex: it checks your lockfiles for this and upgrades it.
  1. On < 1.43.0: Upgrade strands-agents to 1.43.0 or later, commit the lockfile and redeploy.
  2. On < 1.5.0: Upgrade @strands-agents/sdk to 1.5.0 or later, commit the lockfile and redeploy.
  3. If a vulnerable version was live, check your logs and rotate the secrets that server could read.

The advisory

**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.

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References

Merged from GitHub Advisory Database, OSV. Last updated 26 Oct 2026. All vulnerabilities · RSS · JSON

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