HTTP Request Smuggling The advisory has been revoked - it doesn't affect any version of package webrick (opens in a new tab)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-RUBY-WEBRICK-17808181
- published3 Jul 2026
- disclosed2 Jul 2026
- creditUnknown
Introduced: 2 Jul 2026
NewCVE-2026-38969 (opens in a new tab)Amendment
This was deemed not a vulnerability.
Overview
webrick is a HTTP server toolkit that can be configured as an HTTPS server, a proxy server, and a virtual-host server.
Affected versions of this package are vulnerable to HTTP Request Smuggling in the request process. An attacker can bypass request boundaries and interfere with HTTP request processing by sending specially crafted requests containing a trailer Content-Length header.
Project maintainers' note: If you are using webrick in an environment where this pull request would matter, you should move to another Ruby webserver as soon as possible. I understand that such a migration can be challenging, but if you value security at all, you should not be using webrick in production. Webrick is not for production use, as stated in the README.