CVE-2026-41417 Netty vulnerable to HTTP request smuggling and RTSP request injection via DefaultHttpRequest.setUri()
Attackers can inject CRLF characters via setUri() to perform HTTP request smuggling or RTSP request injection in applications using Netty.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-41417?
CVE-2026-41417 is a medium-severity vulnerability in Netty Netty, published on 6 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-41417?
4 open source packages ship an affected version, including io.netty:netty-codec-http. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
io.netty:netty-codec-http Maven | All versions | 4.1.133.Final |
io.netty:netty-codec-http Maven | All versions | 4.1.133.Final |
io.netty:netty-codec-http Maven | From 4.2.0.Alpha1 | 4.2.13.Final |
io.netty:netty-codec-http Maven | From 4.2.0.Alpha1 | 4.2.13.Final |
Products include Netty Netty.
How do I fix CVE-2026-41417?
Upgrade io.netty:netty-codec-http to a fixed version for your release line: 4.1.133.Final or 4.2.13.Final.
Is CVE-2026-41417 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-41417 exists.
Other vulnerabilities in Netty Netty
- CVE-2026-75595 Netty: SNI Routing Bypass via Fragmented TLS ClientHello Causing Fallback to Default SslContext
- CVE-2026-75596 Netty: Fragmented ClientHello records trigger quadratic pre-handshake reassembly in default SNI parsing
- CVE-2026-59901 Netty Bzip2Decoder: Infinite Loop in RLE State Machine Leads to Event-Loop Thread Hang
- CVE-2026-55851 Netty codec-haproxy: Signed-Byte Sentinel Collision in HAProxyMessageDecoder Leads to Unbounded Memory Exhaustion
- CVE-2026-56745 Netty SpdyHttpDecoder: ByteBuf Reference Leak on RST_STREAM Leads to Native Memory Exhaustion
Sources
Also known as CLEANSTART-2026-DD24973, CLEANSTART-2026-FP29744, CLEANSTART-2026-KY86069, CLEANSTART-2026-VY95094, CLEANSTART-2026-WC20717, CLSA-2026-1792692911 and 99 more.