# Commercial @commercial/subtext prototype pollution in multipart parsing

Source: https://junglewise.ai/threats/commercial-commercial-subtext-prototype-pollution-in-multipart-parsing-aa7a56bc  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2020-09-03. Updated: 2026-05-14  
License: CC BY 4.0 with a link back

Severity: info · Published 2020-09-03

@commercial/subtext is a library used to parse incoming web request payloads. A vulnerability in how it handles multipart data allows an attacker to manipulate the internal structure of the application's data objects. This can lead to application crashes (denial of service) or the bypassing of security validation rules, potentially exposing private information or allowing unauthorized actions.

Technologies: [@commercial/subtext (npm)](https://junglewise.ai/threats/technologies/commercial-subtext). Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is This vulnerability exploited in the wild?** No. Junglewise Threat Intelligence has no report of This vulnerability being exploited in the wild.

**How severe is This vulnerability?** Informational severity, published 3 September 2020.

**Which products and versions are affected?** @commercial/subtext (npm) SEMVER:introduced=0,fixed=5.1.2.

**Is there a fix for This vulnerability?** Yes. @commercial/subtext (npm): upgrade to 5.1.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is This vulnerability attacked?** It is attacked over the network, in a software library.

**Am I affected?** Check whether you run @commercial/subtext (npm) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- @commercial/subtext (npm): upgrade to 5.1.2 or later

  ```sh
  npm install @commercial/subtext@5.1.2
  ```


## Technical details

A prototype pollution vulnerability exists in @commercial/subtext versions prior to 5.1.2. An attacker can construct a malicious multipart payload where one of the parts is used to set the prototype of the entire payload object. If the injected prototype contains specific data, it can be used to bypass validation logic that relies on object properties for access control or privacy. Alternatively, if the prototype is set to null, it can trigger unhandled exceptions and a denial-of-service state when the application attempts to access the request payload. The issue is fixed in version 5.1.2.

## Affected products

- Commercial @commercial/subtext < 5.1.2

## Timeline

- 2020-08-31: advisory: GitHub reviewed the advisory
- 2020-09-03: disclosed: Advisory published via GHSA

## References

- [https://www.npmjs.com/advisories/1484](https://www.npmjs.com/advisories/1484)

## Related threats

- [@commercial/subtext denial of service in payload handling](https://junglewise.ai/threats/commercial-subtext-denial-of-service-in-payload-handling-accfbde9)
- [@commercial/subtext denial of service via Content-Encoding header](https://junglewise.ai/threats/commercial-subtext-denial-of-service-via-content-encoding-header-7155598d)