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.
Affected products
netty: netty
References2
- github.com/netty/netty/security/advisories/GHSA-v8h7-rr48-vmmv ExploitMitigationVendor Advisory
- github.com/netty/netty/security/advisories/GHSA-v8h7-rr48-vmmv ExploitMitigationVendor Advisory
Metrics
- CVSS 3.1
-
5.3
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N - EPSS — exploit probability
- 0% percentile: 25 · as of 13 November 2026
- CWE
- CWE-93CWE-444
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.