# Node.js 27.0.0-alpha ships V8 15.6, native fs.glob, ends OpenSSL engine support

> **Key takeaway:** Node.js 27.0.0-alpha.0.0.0 introduces V8 15.6 with new iterator methods and changed memory accounting, implements native filesystem globbing, removes OpenSSL engine support entirely, and marks Intel macOS as experimental.

**Published:** 2026-10-29T19:52:29+00:00 
**Source:** Node.js Official Releases 
**Category:** software-engineering 
**Canonical URL:** https://fosswire.org/news/nodejs-2700-alpha-ships-v8-156-native-fsglob-ends-openssl-en.html 

## Summary
Node.js has published the first alpha for version 27.0.0, a semver-major release led by Rafael Gonzaga that upgrades the JavaScript engine from V8 14.6 to 15.6.75.13 and introduces substantial breaking changes across cryptography, networking, and filesystem APIs. The V8 update enables several ECMAScript features by default including Math.sumPrecise(), Iterator.prototype.join(), and Iterator.zip(), while changing how heap limits are calculated when --max-old-space-size is unspecified and altering serialization formats that break compatibility with older Node.js versions.

Beyond the engine, this alpha removes the bundled FIPS provider build, ends all OpenSSL engine support, requires OpenSSL 3 or later, and upgrades the bundled OpenSSL sources to 4.1.0. The fs module gains a native glob implementation, the domain module is runtime-deprecated and ported to AsyncLocalStorage, and Intel macOS support is downgraded to experimental status. Multiple HTTP and networking defaults change, including increased keepAliveTimeout and HTTP/2 window sizes.

## What changes in Node.js 27.0.0-alpha
- **V8 15.6 engine upgrade:** The runtime moves from V8 14.6 to 15.6.75.13, enabling Math.sumPrecise(), Intl.Locale.prototype.variants, Iterator.prototype.join(), Iterator.prototype.includes(), Iterator.zip(), and Iterator.zipKeyed() without flags. Experimental features behind new flags include import defer, Immutable ArrayBuffer, and RegExp buffer boundaries.
- **Memory and heap accounting changes:** When --max-old-space-size is not explicitly set, the default heap limit becomes half of physical memory clamped between 256 MB and 4 GB. Buffer and ArrayBuffer memory now counts toward this heap limit, which may cause out-of-memory errors in applications that previously relied on the old behavior.
- **Serialization format incompatibility:** v8.serialize(), structuredClone(), and postMessage() use a new serialization format that older Node.js releases cannot deserialize. The compile cache and v8.cachedDataVersionTag() now invalidate on every Node.js patch containing V8 changes, not only on V8 version bumps.
- **Cryptography and OpenSSL overhaul:** The release removes the bundled FIPS provider build, drops OpenSSL 1.x code paths entirely, ends OpenSSL engine support in crypto/https/tls, requires OpenSSL 3 or later, and upgrades bundled OpenSSL to 4.1.0. Multiple deprecated crypto APIs move to End-of-Life including DEP0093, DEP0198, DEP0203, and DEP0204.
- **Filesystem and networking API changes:** The fs module implements native glob functionality. HTTP keepAliveTimeout defaults increase to 65 seconds, HTTP/2 default window sizes increase, req.headers objects now have a null prototype, and the experimental net/promises API is added. The domain module is runtime-deprecated and reimplemented atop AsyncLocalStorage.

## Why it matters
For JavaScript and TypeScript developers running server-side applications, the V8 serialization format change and altered heap accounting represent the most disruptive modifications, requiring explicit --max-old-space-size configuration and preventing rolling back to older Node.js versions for cached data. The removal of OpenSSL engine support and deprecation of the domain module will force enterprise deployments and legacy applications to migrate to Web Crypto or AsyncLocalStorage patterns before Node.js 27 reaches LTS status. The native fs.glob implementation reduces dependency on external packages like glob and fast-glob, while the net/promises API continues Node.js's gradual migration toward standard Promise-based networking interfaces.