CVE-2018-14731

Name: CVE-2018-14731
Creator: NVD / NIST
Published: 2018-09-21T17:29:05.14+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

UnknownEPSS 2.33%

Last modified Jun 17, 2026

CVE-2018-14731 is a vulnerability of currently unknown severity. An issue was discovered in HMRServer.js in Parcel parcel-bundler. Attackers are able to steal developer's code because the origin of requests is not checked by the WebSocket server, which is used for HMR (Hot Module Replacement). EPSS estimates a 2.33% chance of exploitation in the next 30 days.

Description

An issue was discovered in HMRServer.js in Parcel parcel-bundler. Attackers are able to steal developer's code because the origin of requests is not checked by the WebSocket server, which is used for HMR (Hot Module Replacement). Anyone can receive the HMR message sent by the WebSocket server via a ws://127.0.0.1 connection (with a random TCP port number) from any origin. The random port number can be found by connecting to http://127.0.0.1 and reading the "new WebSocket" line in the source code.

Metrics

EPSS Probability

2.33%

81.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-200

Affected Software

Vendor	Product	Versions
Parceljs	Parcel	All versions

References

https://blog.cal1.cn/post/Sniffing%20Codes%20in%20Hot%20Module%20Reloading%20MessagesExploit, Third Party Advisory
https://github.com/parcel-bundler/parcel/issues/1783Vendor Advisory
https://github.com/parcel-bundler/parcel/pull/1794Exploit, Patch, Vendor Advisory
https://blog.cal1.cn/post/Sniffing%20Codes%20in%20Hot%20Module%20Reloading%20MessagesExploit, Third Party Advisory
https://github.com/parcel-bundler/parcel/issues/1783Vendor Advisory
https://github.com/parcel-bundler/parcel/pull/1794Exploit, Patch, Vendor Advisory

Timeline

Published: Sep 21, 2018
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-14731?

How severe is CVE-2018-14731?

Severity scoring for CVE-2018-14731 is pending analysis. The EPSS model estimates a 2.33% probability of exploitation in the next 30 days.

How do I fix CVE-2018-14731?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2018-14731?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST