CVE-2026-41417
Netty: Start-Line Injection in DefaultHttpRequest.setUri() Allows HTTP Request Smuggling and RTSP Request Injection
Description
Netty allows request-line validation to be bypassed when a `DefaultHttpRequest` or `DefaultFullHttpRequest` is created first and its URI is later changed via `setUri()`. The constructors reject CRLF and whitespace characters that would break the start-line, but `setUri()` does not apply the same validation. `HttpRequestEncoder` and `RtspEncoder` then write the URI into the request line verbatim. If attacker-controlled input reaches `setUri()`, this enables CRLF injection and insertion of additional HTTP or RTSP requests, leading to HTTP request smuggling or desynchronization on the HTTP side and request injection on the RTSP side. This issue is fixed in versions 4.2.13.Final and 4.1.133.Final.
How to fix CVE-2026-41417
To remediate CVE-2026-41417, upgrade the affected package to a fixed version below.
- —no fix listed
- —upgrade to 4.1.133.Final or later
Is CVE-2026-41417 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0
- from 0, < 4.1.133.Final
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N |