CVE-2018-14731
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).
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.33%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.0
- 7.5 HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- EPSS
- 2.33% probability · 83th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-200
- Affected
- parceljs/parcel
- Source
- cve@mitre.org
EPSS 2.3% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
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
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.