Package Instance

Cross-site Scripting (XSS) in serialize-javascript
A flaw was found in npm-serialize-javascript. The vulnerability occurs because the serialize-javascript module does not properly sanitize certain inputs, such as regex or other JavaScript object types, allowing an attacker to inject malicious code. This code could be executed when deserialized by a web browser, causing Cross-site scripting (XSS) attacks. This issue is critical in environments where serialized data is sent to web clients, potentially compromising the security of the website or web application using this package.

Serialize JavaScript has CPU Exhaustion Denial of Service via crafted array-like objects
### Impact

**What kind of vulnerability is it?**

It is a **Denial of Service (DoS)** vulnerability caused by CPU exhaustion. When serializing a specially crafted "array-like" object (an object that inherits from `Array.prototype` but has a very large `length` property), the process enters an intensive loop that consumes 100% CPU and hangs indefinitely.

**Who is impacted?**

Applications that use `serialize-javascript` to serialize untrusted or user-controlled objects are at risk. While direct exploitation is difficult, it becomes a high-priority threat if the application is also vulnerable to **Prototype Pollution** or handles untrusted data via **YAML Deserialization**, as these could be used to inject the malicious object.

### Patches

**Has the problem been patched?**

Yes, the issue has been patched by replacing `instanceof Array` checks with `Array.isArray()` and using `Object.keys()` for sparse array detection.

**What versions should users upgrade to?**

Users should upgrade to **`v7.0.5`** or later.

### Workarounds

**Is there a way for users to fix or remediate the vulnerability without upgrading?**

There is no direct code-level workaround within the library itself. However, users can mitigate the risk by:

* Validating and sanitizing all input before passing it to the `serialize()` function.
* Ensuring the environment is protected against Prototype Pollution.
* Upgrading to **`v7.0.5`** as soon as possible.

### Acknowledgements

Serialize JavaScript thanks **Tomer Aberbach** (@TomerAberbach) for discovering and privately disclosing this issue.