knowns versions before 0.30.0 fail to validate filesystem paths in MCP tool arguments, allowing attackers to read, create, overwrite and delete files outside the project directory. Attackers can supply path arguments containing directory traversal sequences to access arbitrary Markdown files accessible to the server process.

Affected: npm: knowns

## Overview

Verified. Multiple **Unrestricted Path Traversal** vulnerabilities exist in the Knowns MCP `docs` and `memory` tools, allowing arbitrary file read, write, and deletion operations outside the project sandbox. The storage layer functions (`Get`, `Create`, `Update`, `Rename`, `Delete`) in both `doc_store.go` and `memory_store.go` concatenate user-controlled paths with `filepath.Join()` without any containment validation.

Additionally, the `docs.update` action with a `newPath` parameter performs a file deletion via `Rename()`, but is classified as `CapWrite` in the permission registry rather than `CapDelete`. This allows an attacker with a `read-write-no-delete` preset to bypass deletion restrictions and destroy arbitrary files outside the project root.

## Affected paths

| File Path | Role | Vulnerability & Execution Impact | | :--- | :--- | :--- | | **`internal/storage/doc_store.go`** | Vulnerable Sink (Docs) | **Path Traversal in File Operations (CWE-22):** `Get()`, `Create()`, `Update()`, `Rename()`, `Delete()` join user-controlled `path` with `filepath.Join(ds.docsDir(), ...)` without validating path containment. | | **`internal/storage/memory_store.go`** | Vulnerable Sink (Memory) | **Path Traversal in Memory Operations (CWE-22):** `GetInLayer()`, `Create()`, `Update()`, `Delete()` join user-controlled `id` with `filepath.Join(dir, models.MemoryFileName(id))` without validation. | | **`internal/mcp/handlers/doc.go`** | Pass-Through Handler | **Unsanitized I…