# Deno v1.40.4 — Release & Upgrade Intelligence
- **Product:** Deno (https://deno.com)
- **Version:** v1.40.4
- **Released:** Feb 08, 2024
- **Impact Score:** 5/10
- **Breaking Changes:** Not verified
- **Canonical Analysis:** https://changelogs.us/deno/updates/v1.40.4/

## Executive Summary (TL;DR)
Deno v1.40.4. Source highlight: feat(unstable): `Deno.FsFile.lock[Sync]()` and `Deno.FsFile.unlock[Sync]()`

## New Features
- feat(unstable): `Deno.FsFile.lock[Sync]()` and `Deno.FsFile.unlock[Sync]()`
- feat: ARM64 builds (#22298)

## Improvements
- perf: remove duplicate `env::current_dir` call in package.json search (#22255)

## Bug Fixes
- fix(cli): Add IP address support to DENO_AUTH_TOKEN (#22297)
- fix(ext/node): Ensure os.cpus() works on arm64 linux (#22302)
- fix(ext/node): fix timeout param validation in cp.execFile (#22262)
- fix(jupyter): ensure op is available (#22240)
- fix(lint): point to migration docs in deprecated APIs rule (#22338)
- fix(lsp): disable no-cache diagnostics for jsr specifiers (#22284)