CVE-2026-93573 — Io.netty/netty-codec-http: netty split transfer-encoding fields bypass final-chunked validation and enable request smuggling
A flaw was found in Netty's HTTP/1.1 decoder. This vulnerability allows a remote attacker to bypass `Transfer-Encoding` header validation by splitting the `Transfer-Encoding` fi…
Published: 2026-09-18 · CVSS: 6.5 · CVSS 3.1
A flaw was found in Netty's HTTP/1.1 decoder. This vulnerability allows a remote attacker to bypass `Transfer-Encoding` header validation by splitting the `Transfer-Encoding` field across multiple headers, with the last field containing a non-final transfer coding like `gzip` or `deflate`. This bypass can lead to HTTP request smuggling, enabling attackers to bypass security controls, desynchronize request processing, or cause requests to be processed in an unintended context.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7