Denial of Service in uws
Affected versions of uws do not properly handle large websocket messages when permessage-deflate is enabled, which may result in a denial of service condition.
If uws recieves a 256Mb websocket message when permessage-deflate is enabled, the server will compress the message prior to executing the length check, and subsequently extract the message prior to processing. This can result in a situation where an excessively large websocket message passes the length checks, yet still gets cast from a Buffer to a string, which will exceed v8's maximum string size and crash the process.
Recommendation
Update to version 0.10.9 or later.
Alternatively, disable permessage-deflate.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | uws | >= 0.10.0, < 0.10.9 | 0.10.9 |
References
- Weakness (CWE)
CWE-400- Platform
- npm
- Package
uws- Disclosed
- 01.09.2020
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-hf5h-hh56-3vrg - CC BY 4.0
Vulnerability history: uws
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
This is the only known vulnerability of this package.
Know which vulnerabilities affect your application
With the DockRay integration and software inventory enabled, DockRay checks reported component versions against known vulnerabilities and notifies you about confirmed matches. Coverage depends on the supported technology and available advisory data.