Express

Async promise errors not caught in Express 4

critical
availabilityUpdated Feb 6, 2026(via Exa)
Technologies:
How to detect:

In Express 4, errors thrown in async functions or rejected promises do not automatically reach error handling middleware, potentially causing unhandled rejections or app crashes

Recommended action:

Wrap async route handlers in try/catch blocks and explicitly call next(err). Alternatively, use an asyncHandler wrapper utility to eliminate boilerplate, or upgrade to Express 5 which automatically catches promise rejections