Executive brief
atototo api-lab-mcp is a tool used to test and debug APIs through natural language interfaces. A security vulnerability allows remote attackers to force the server to make unauthorized requests to internal systems or external websites. This could lead to the exposure of sensitive internal data, access to private cloud metadata, or service disruptions.
Technical details
A Server-Side Request Forgery (SSRF) vulnerability exists in atototo api-lab-mcp versions up to 0.2.1. The vulnerability is located in the HTTP Interface component, specifically within the functions analyze_api_spec, generate_test_scenarios, and test_http_endpoint across several files including src/mcp/http-server.ts and src/mcp/server.ts. The root cause is the lack of sanitization for the 'source' and 'url' arguments, which are passed directly to outbound request sinks like fetch and axios. A remote, unauthenticated attacker can exploit this by providing a malicious URL, potentially accessing internal services, cloud metadata endpoints (e.g., IMDS), or bypassing network segmentation. As of the advisory date, no official patch has been released by the maintainer.
Affected products
- atototo api-lab-mcp up to 0.2.1
Timeline
- 2026-03-17: disclosed: Vulnerability reported to the project maintainer via GitHub issue.
- 2026-03-26: other: Public exploit details shared on GitHub.
- 2026-04-09: advisory: CVE-2026-5832 published.