Is mcp-handler safe?
- Node.js filesystem read
- Node.js filesystem write/delete
- Node.js network egress
What to do: Nothing here argues against installing it. Grant the capabilities it lists only if you expect the tool to need them.
mcp-handler is an npm package analyzed by SkillTotal's deterministic static scanner. The scan found no malicious indicators. It can: filesystem read, filesystem write, mcp tools detected and network egress — capabilities are what the code can do, not a verdict on intent. Risk score 0/100 (low).
mcp-handler 2.3.0
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Automated static-analysis result. It can contain false positives and false negatives, and is not a claim about the intent of mcp-handler's authors. Report a false positive.
Behavioral traits
How this component maps to the CSA agentic threat model. Descriptive — it never affects the risk score.
Findings (4)
The component reads files from disk.
await fs.readFile(path.join(process.cwd(), "package.json"), "utf-8")
Why it matters: Usually legitimate, but worth confirming it can't be steered into reading sensitive files.
Fix: Confirm which files are read and that paths cannot be influenced by untrusted input to reach sensitive locations.
The component writes or deletes files on disk.
await fs.writeFile(routeFilePath, ROUTE_TEMPLATE);
Why it matters: Usually legitimate, but worth confirming the paths can't be controlled by untrusted input.
Fix: Confirm which files are written/deleted and that paths cannot be influenced by untrusted input.
The component makes outbound network requests.
const res = await fetch(config.endpoint, {const response = await sdkHandler.fetch(req, {const res = await fetch(config.endpoint, {const response = await sdkHandler.fetch(req, {Why it matters: Usually legitimate, but confirm the destinations are expected and no sensitive data leaves.
Fix: Confirm the destination hosts are expected and that no sensitive data is sent off-host.
An MCP tool surface (manifest or tool definitions) was found.
server.registerTool(
{"version":3,"sources":["../../src/cli/index.ts"],"names":[],"mappings":";;;;;;AAEA,SAAS,eAAe;AACxB,OAAO,QAAQ;AACf,OAAO,UAAU;AACjB,OAAO,WAAW;AALlB;AAAA;AAOA,QAAM,UAAU,IAAI,QAAQ;AAE5B,QAAM,iBAAiB;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA; …server.registerTool(
{"version":3,"sources":["../../src/cli/index.ts"],"names":[],"mappings":";;;;;;AAEA,SAAS,eAAe;AACxB,OAAO,QAAQ;AACf,OAAO,UAAU;AACjB,OAAO,WAAW;AALlB;AAAA;AAOA,QAAM,UAAU,IAAI,QAAQ;AAE5B,QAAM,iBAAiB;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA;AAAA; …await provider.registerTool({{"version":3,"sources":["../src/handler/mcp-api-handler.ts","../src/lib/log-helper.ts","../src/webmcp/script-handler.ts","../src/handler/index.ts","../src/events/register.ts","../src/events/schemas.ts","../src/events/json.ts","../src/events …{"version":3,"sources":["../src/handler/mcp-api-handler.ts","../src/lib/log-helper.ts","../src/webmcp/script-handler.ts","../src/handler/index.ts","../src/events/register.ts","../src/events/schemas.ts","../src/events/json.ts","../src/events …await provider.registerTool({const server = new McpServer(serverInfo, mcpServerOptions);
{"version":3,"sources":["../src/handler/mcp-api-handler.ts","../src/lib/log-helper.ts","../src/webmcp/script-handler.ts","../src/handler/index.ts","../src/events/register.ts","../src/events/schemas.ts","../src/events/json.ts","../src/events …{"version":3,"sources":["../src/handler/mcp-api-handler.ts","../src/lib/log-helper.ts","../src/webmcp/script-handler.ts","../src/handler/index.ts","../src/events/register.ts","../src/events/schemas.ts","../src/events/json.ts","../src/events …Why it matters: Just context — review which tools it offers and their permissions.
Fix: Review the declared MCP tools and their permissions.
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