Request-Smuggling

A vulnerability exists where HTTP/1 authority-form CONNECT requests are incorrectly translated into malformed HTTP/2 CONNECT requests, allowing for attacker control over the :authority header and potential request smuggling.

The http4s Ember HTTP/1.1 parser fails to reject messages containing both 'Transfer-Encoding' and 'Content-Length' headers, enabling CL.TE request smuggling attacks.

Tornado versions prior to 6.4.1 are vulnerable to HTTP request smuggling via the improper processing of duplicate 'Transfer-Encoding: chunked' headers when deployed behind a proxy.

Traefik fails to isolate connection-bound NTLM and Negotiate authentication on HTTP/3 routes, allowing unrelated clients to inherit victim-authenticated backend connections.

Five independent HTTP/1.1 conformance laxities in Blaze's Java parser cause request-boundary disagreement with a stricter intermediary proxy, enabling front-end ACL/authentication bypass, response-queue poisoning on pooled backend connections, and cache poisoning in affected `http4s-blaze-server` and `blaze-http` components.

A high-severity vulnerability, CVE-2026-38969, exists in Ruby WEBrick versions up to v1.9.2 due to improper re-parsing of the 'trailer Content-Length' header, enabling HTTP request smuggling that attackers can exploit to bypass security controls and gain unauthorized access or execute arbitrary requests.

CVE-2025-23167 describes a request smuggling vulnerability in Node.js 20's HTTP parser due to improper header termination, allowing attackers to bypass proxy access controls.

A request smuggling vulnerability exists in Siemens SENTRON 7KT PAC1261 Data Manager before V2.1.0, due to the web server improperly accepting a bare LF as a line terminator in chunked data chunk-size lines, potentially allowing an attacker to retrieve authorization tokens and gain administrative control over the device.

Jetty is vulnerable to HTTP request smuggling due to improper parsing of quoted strings in HTTP/1.1 chunked transfer encoding extension values, potentially allowing attackers to inject arbitrary HTTP requests, poison caches, and bypass security controls.

Eclipse Jetty's HTTP/1.1 parser is vulnerable to request smuggling due to improper handling of chunk extensions, allowing attackers to inject malicious requests.

A remote attacker can exploit multiple vulnerabilities in Apache Traffic Server to conduct a denial of service or request smuggling attack.

CVE-2026-28368 is a vulnerability in Undertow that allows a remote attacker to construct specially crafted requests, leading to request smuggling attacks and potential bypass of security controls, resulting in unauthorized resource access.

A remote attacker can exploit CVE-2026-28367 in Undertow by sending '\r\r\r' as a header block terminator, leading to request smuggling on vulnerable proxy servers.

Netty incorrectly parses quoted strings in HTTP/1.1 chunked transfer encoding extension values, enabling request smuggling attacks by terminating chunk header parsing at \r\n inside quoted strings instead of rejecting the malformed request.