In Node.js Buffer is an abstraction over RAM, therefore if you allocate it in an unsafe way, there is a high risk of having even some source code in the buffer instance. Try running console.log(Buffer.allocUnsafe(10000).toString('utf-8')) and I guarantee that you will see some code in your stdout.

Allocation is a synchronous operation and we know that single threaded Node.js doesn't really feel good about synchronous stuff. Unsafe allocation is much faster than safe, because the buffer santarization step takes time. Safe allocation is, well, safe, but there is a performance trade off.

I'd suggest sticking to safe allocation first and if you end up with low performance, you can think of ways to implement unsafe allocation, without exposing private stuff. Just keep in mind that allocUnsafe method has the word unsafe for a reason. E.g, if you are going to pass some compliance certification like PCI DSS, I'm pretty sure QSA will notice that and will have a lot of questions.

Answer from Vladyslav Usenko on Stack Overflow
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Node.js
nodejs.org › api › buffer.html
Buffer | Node.js v26.11.1 Documentation
The Buffer module pre-allocates an internal Buffer instance of size Buffer.poolSize that is used as a pool for the fast allocation of new Buffer instances created using Buffer.allocUnsafe(), Buffer.from(array), Buffer.from(string), and Buffer.concat() only when size is less than Buffer.poolSize ...
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W3Schools
w3schools.com › nodejs › met_buffer_alloc.asp
Node.js Buffer.alloc() Method
The Buffer.alloc() method creates a new buffer object of the specified size.
      » npm install buffer-alloc
    
Published: May 29, 2018
Version: 1.2.0
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In Node.js Buffer is an abstraction over RAM, therefore if you allocate it in an unsafe way, there is a high risk of having even some source code in the buffer instance. Try running console.log(Buffer.allocUnsafe(10000).toString('utf-8')) and I guarantee that you will see some code in your stdout.

Allocation is a synchronous operation and we know that single threaded Node.js doesn't really feel good about synchronous stuff. Unsafe allocation is much faster than safe, because the buffer santarization step takes time. Safe allocation is, well, safe, but there is a performance trade off.

I'd suggest sticking to safe allocation first and if you end up with low performance, you can think of ways to implement unsafe allocation, without exposing private stuff. Just keep in mind that allocUnsafe method has the word unsafe for a reason. E.g, if you are going to pass some compliance certification like PCI DSS, I'm pretty sure QSA will notice that and will have a lot of questions.

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Buffer.alloc(size, fill, encoding) -> returns a new initialized Buffer of the specified size. This method is slower than Buffer.allocUnsafe(size) but guarantees that newly created Buffer instances never contain old data that is potentially sensitive.

Buffer.allocUnsafe(size) -> the Buffer is uninitialized, the allocated segment of memory might contain old data that is potentially sensitive. Using a Buffer created by Buffer.allocUnsafe() without completely overwriting the memory can allow this old data to be leaked when the Buffer memory is read.

Note: While there are clear performance advantages to using Buffer.allocUnsafe(), extra care must be taken in order to avoid introducing security vulnerabilities into an application

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GeeksforGeeks
geeksforgeeks.org › node.js › node-js-buffer-alloc-method
Node.js Buffer.alloc() Method - GeeksforGeeks
October 12, 2021 - // Node.js program to demonstrate the // Buffer.alloc() Method // Allocate buffer of given size // using buffer.alloc() method var buf = Buffer.alloc(6, 'a'); // Prints <Buffer 61 61 61 61 61> console.log(buf); Output: <Buffer 61 61 61 61 61> Reference: https://nodejs.org/docs/latest-v11.x/api/buffer.html#buffer_class_method_buffer_alloc_size_fill_encoding
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GitHub
github.com › LinusU › buffer-alloc
GitHub - LinusU/buffer-alloc: A ponyfill for Buffer.alloc · GitHub
const alloc = require('buffer-alloc') console.log(alloc(4)) //=> <Buffer 00 00 00 00> console.log(alloc(6, 0x41)) //=> <Buffer 41 41 41 41 41 41> console.log(alloc(10, 'linus', 'utf8')) //=> <Buffer 6c 69 6e 75 73 6c 69 6e 75 73>
Author: LinusU
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LogRocket
blog.logrocket.com › home › node.js buffer: a complete guide
Node.js buffer: A complete guide - LogRocket Blog
June 4, 2024 - The Buffer.alloc() method creates a new buffer of any size. When you use this method, you assign the size of the buffer in bytes.
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Educative
educative.io › answers › what-is-bufferalloc-in-nodejs
What is Buffer.alloc in Node.js?
The Buffer.alloc function is part of the Buffer module in Node.js and is used to allocate a buffer of any size less than the constant value of buffer.constants.MAX_LENGTH.
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GitHub
github.com › LinusU › buffer-alloc › blob › master › readme.md
buffer-alloc/readme.md at master · LinusU/buffer-alloc
const alloc = require('buffer-alloc') console.log(alloc(4)) //=> <Buffer 00 00 00 00> console.log(alloc(6, 0x41)) //=> <Buffer 41 41 41 41 41 41> console.log(alloc(10, 'linus', 'utf8')) //=> <Buffer 6c 69 6e 75 73 6c 69 6e 75 73>
Author: LinusU
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DeepSource
deepsource.com › directory › javascript › issues › JS-D025
Avoid the use of `Buffer()` and `Buffer#allocUnsafe()` (JS-D025) ・ JavaScript
Buffer.alloc(size[, fill[, encoding]]) returns a new initialized Buffer of the specified size. This method is slower than Buffer.allocUnsafe(size) but guarantees that newly created Buffer instances never contain potentially sensitive data.
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NodeSource
nodesource.com › blog › understanding-the-buffer-deprecation-in-node-js-10
Understanding the Buffer Deprecation in Node.js 10
April 18, 2018 - Buffer.from() // Creates a new Buffer from the provided string, array of UTF-8 octets, an ArrayBuffer, or another Buffer. Buffer.alloc() // Creates a new, initialized Buffer of the specified length. Zero filled by default.
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npm
npmjs.com › package › buffer-alloc-unsafe
buffer-alloc-unsafe - npm
Allocates a new non-zero-filled Buffer of size bytes. The size must be less than or equal to the value of buffer.kMaxLength and greater than or equal to zero.
      » npm install buffer-alloc-unsafe
    
Published: May 29, 2018
Version: 1.1.0
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DigitalOcean
digitalocean.com › community › tutorials › using-buffers-in-node-js
Using Buffers in Node.js | DigitalOcean
May 1, 2020 - To create a new buffer, we used the globally available Buffer class, which has the alloc() method.
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2coffee
2coffee.dev › en › articles › buffers-in-nodejs-how-to-use-buffers
Buffers in Node.js, How to Use Buffers?
January 5, 2024 - Both alloc and allocUnsafe methods allocate a Buffer of the specified size in bytes. The Buffer created by alloc is initialized with zeroes, and the Buffer created by allocUnsafe is not initialized.
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GitHub
github.com › LinusU › buffer-alloc-unsafe
GitHub - LinusU/buffer-alloc-unsafe: A ponyfill for Buffer.allocUnsafe · GitHub
size <Integer> The desired length of the new Buffer · Allocates a new non-zero-filled Buffer of size bytes. The size must be less than or equal to the value of buffer.kMaxLength and greater than or equal to zero.
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Medium
medium.com › @ks.deepak07 › understanding-node-js-buffers-69b0adae2005
Understanding Node.js Buffers | by Deepak Kumar Singh | Medium
May 4, 2025 - The Buffer.alloc() static method creates a new empty buffer object of the specified size.
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YouTube
youtube.com › shorts › d5amlzwtVMA
Buffer Alloc method to allocate memory using Nodejs - YouTube
In this video we will see Github Link: HireAPI Node Project: https://github.com/leelawebdev/hireapiInstagram: https://www.instagram.com/leelawebdev/Telegram:
Published: March 20, 2025