Executive brief
Braffolk mcp-summarization-functions is a utility used to summarize data via the Model Context Protocol (MCP). A security flaw allows an attacker to execute unauthorized system commands by providing malicious input to the tool's summarization feature. This could lead to a total takeover of the server, unauthorized access to sensitive data, or disruption of services.
Technical details
An OS command injection vulnerability (CWE-78) exists in Braffolk mcp-summarization-functions versions up to 0.1.5. The flaw is located in the `summarize_command` component within `src/server/mcp-server.ts`. Specifically, the `command` argument provided via MCP/HTTP requests is passed unsanitized to the `execa` function at line 322. While some advisories suggest local access is required, the technical report indicates that any attacker capable of invoking the MCP/HTTP endpoint can achieve arbitrary code execution with the privileges of the server process. As of the disclosure, no official patch has been released by the vendor.
Affected products
- Braffolk mcp-summarization-functions up to 0.1.5
Timeline
- 2026-03-17: disclosed: Vulnerability reported by independent researcher BruceJin
- 2026-03-22: other: Public exploit details published on GitHub
- 2026-04-06: advisory: CVE-2026-5619 published