# CVE-2020-7639: eivindfjeldstad-dot prototype pollution

Source: https://junglewise.ai/threats/cve-2020-7639-eivindfjeldstad-dot-prototype-pollution  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2021-05-25. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2020-7639 · Severity: low · CVSS 3.1 · Published 2021-05-25

dot is a lightweight JavaScript utility library for manipulating object properties. A prototype pollution vulnerability in the set() function could allow attackers to modify the shared Object.prototype, affecting all objects in an application and potentially causing unexpected behavior or enabling privilege escalation.

Vendors: [npm](https://junglewise.ai/threats/vendors/npm).

## Quick answers

**Is CVE-2020-7639 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2020-7639 being exploited in the wild.

**How severe is CVE-2020-7639?** Low severity, with a CVSS score of 3.1, published 25 May 2021.

**Which products and versions are affected?** @eivifj/dot (npm) SEMVER:introduced=0,fixed=1.0.3.

**Is there a fix for CVE-2020-7639?** Yes. @eivifj/dot (npm): upgrade to 1.0.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2020-7639 attacked?** It is attacked over the network.

**Am I affected by CVE-2020-7639?** Check whether you run @eivifj/dot (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

- @eivifj/dot (npm): upgrade to 1.0.3 or later

  ```sh
  npm install @eivifj/dot@1.0.3
  ```


## Technical details

The vulnerability is a prototype pollution flaw (CWE-1321, CWE-915) in the set() function of eivindfjeldstad-dot versions below 1.0.3. The function fails to sanitize the __proto__ payload when processing object paths, allowing an attacker to inject properties into Object.prototype. Since the vulnerable function is directly callable with untrusted input (likely network-reachable via Node.js applications), an attacker can craft a malicious path string to pollute the prototype chain. The fix, committed on 2020-02-22, adds validation to prevent __proto__ key pollution. No authentication or user interaction is required to trigger the vulnerability.

## Affected products

- eivindfjeldstad dot below 1.0.3

## Identifiers

- CVE-2020-7639
- GHSA-wfwq-xc57-fq7v

## Timeline

- 2020-04-06: disclosed
- 2020-02-22: patched: Fix committed; version 1.0.3 released
- 2021-05-25: advisory

## References

- [https://github.com/eivindfjeldstad/dot/commit/774e4b0c97ca35d2ae40df2cd14428d37dd07a0b](https://github.com/eivindfjeldstad/dot/commit/774e4b0c97ca35d2ae40df2cd14428d37dd07a0b)