CWE-444— Inconsistent Interpretation of HTTP Requests (HTTP Request Smuggling)

Emby Server is a user-installable home media server which stores and organizes a user's media files of virtually any format and makes them available for viewing at home and abroad on a broad range of client devices. This vulnerability may …

HAProxy before 2.7.3 may allow a bypass of access control because HTTP/1 headers are inadvertently lost in some situations, aka "request smuggling." The HTTP header parsers in HAProxy may accept empty header field names, which could be use…

Symantec Advanced Secure Gateway (ASG) and ProxySG are susceptible to an HTTP desync vulnerability. When a remote unauthenticated attacker and other web clients communicate through the proxy with the same web server, the attacker can send …

Puma is a simple, fast, multi-threaded, parallel HTTP 1.1 server for Ruby/Rack applications. When using Puma behind a proxy that does not properly validate that the incoming HTTP request matches the RFC7230 standard, Puma and the frontend …

In Varnish Cache before 6.6.2 and 7.x before 7.0.2, Varnish Cache 6.0 LTS before 6.0.10, and and Varnish Enterprise (Cache Plus) 4.1.x before 4.1.11r6 and 6.0.x before 6.0.9r4, request smuggling can occur for HTTP/1 connections.

Pound before 2.8 allows HTTP request smuggling, a related issue to CVE-2016-10711.

HttpObjectDecoder.java in Netty before 4.1.44 allows a Content-Length header to be accompanied by a second Content-Length header, or by a Transfer-Encoding header.

HttpObjectDecoder.java in Netty before 4.1.44 allows an HTTP header that lacks a colon, which might be interpreted as a separate header with an incorrect syntax, or might be interpreted as an "invalid fold."

Apache Traffic Server forwards malformed HTTP chunked trailer section to origin servers. This can be utilized for request smuggling and may also lead cache poisoning if the origin servers are vulnerable. This issue affects Apache Traffic …

HTTP request/response smuggling vulnerability in HAProxy version 2.7.0, and 2.6.1 to 2.6.7 allows a remote attacker to alter a legitimate user's request. As a result, the attacker may obtain sensitive information or cause a denial-of-servi…

The llhttp parser <v14.20.1, <v16.17.1 and <v18.9.1 in the http module in Node.js does not correctly handle multi-line Transfer-Encoding headers. This can lead to HTTP Request Smuggling (HRS).

The llhttp parser <v14.20.1, <v16.17.1 and <v18.9.1 in the http module in Node.js does not strictly use the CRLF sequence to delimit HTTP requests. This can lead to HTTP Request Smuggling (HRS).

The llhttp parser <v14.20.1, <v16.17.1 and <v18.9.1 in the http module in Node.js does not correctly parse and validate Transfer-Encoding headers and can lead to HTTP Request Smuggling (HRS).

Apache HTTP Server versions 2.4.20 to 2.4.43. A specially crafted value for the 'Cache-Digest' header in a HTTP/2 request would result in a crash when the server actually tries to HTTP/2 PUSH a resource afterwards. Configuring the HTTP/2 f…

Apache Traffic Server can return an origin connection to the shared pool while the origin is still waiting on a request body the client declared but never fully sent, including when the client used Expect: 100-continue. The origin then rea…

cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.20.1, cpp-httplib does not have a limit for a unique line, permitting an attacker to explore this to allocate memory arbitrarily. This vulnerabili…

HTTP request desynchronization in Ping Identity PingAccess, all versions prior to 8.0.1 affected allows an attacker to send specially crafted http header requests to create a request smuggling condition for proxied requests.

In the web management interface in Foscam C1 Indoor HD cameras with application firmware 2.52.2.37, a specially crafted HTTP request can allow for a user to inject arbitrary characters in the pureftpd.passwd file during a username change, …

Dell EMC PV ME5, versions ME5.1.0.0.0 and ME5.1.0.1.0, contains a Client-side desync Vulnerability. An unauthenticated attacker could potentially exploit this vulnerability to force a victim's browser to desynchronize its connection with …

When a client sends a POST with Expect: 100-continue and the origin answers before reading the body, Apache Traffic Server parses the unread body left on the client connection as the next request. An attacker behind a front-end proxy that …

Summary Before version 0.9.0, the HTTP/1 upstream path in pingora-proxy passed the downstream request through upstream_request_filter and wrote it to the upstream without removing the client's Connection header, other hop-by-hop headers…

Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, Ember’s HTTP/1.1 parser accepts differing duplicate Content-Length headers and uses the last value instead of rejecting the message. When an Ember server is b…

Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, Ember’s HeaderP.parse uses a case-sensitive substring test for the Transfer-Encoding value and decodes header bytes with the platform default charset. Values …

IBM WebSphere Application Server and IBM WebSphere Application Server - Liberty is vulnerable to HTTP Response Smuggling due to improper handling of non-standard HTTP version tokens.

IBM WebSphere Application Server and IBM WebSphere Application Server - Liberty is vulnerable to HTTP request smuggling due to improper handling of TRACE requests.

Skipper is an HTTP router and reverse proxy for service composition. Prior to 0.26.10, zalando/skipper's OpenPolicyAgent integration silently bypasses request-body inspection on HTTP/1.1 Transfer-Encoding: chunked and HTTP/2 requests that …

@fastify/reply-from v12.6.1 and earlier and @fastify/http-proxy v11.4.3 and earlier process the client's Connection header after the proxy has added its own headers via rewriteRequestHeaders. This allows attackers to retroactively strip pr…

Spring Cloud Gateway Server forwards the X-Forwarded-For and Forwarded headers from untrusted proxies.

This vulnerability allows a high-privileged authenticated PAM user to achieve remote command execution on the affected PAM system by sending a specially crafted HTTP request.

An unauthenticated attacker in SAP Web Dispatcher - versions WEBDISP 7.49, WEBDISP 7.53, WEBDISP 7.54, WEBDISP 7.77, WEBDISP 7.81, WEBDISP 7.85, WEBDISP 7.88, WEBDISP 7.89, WEBDISP 7.90, KERNEL 7.49, KERNEL 7.53, KERNEL 7.54 KERNEL 7.77, K…

Within the Umbraco CMS, a configuration element named "UmbracoApplicationUrl" (or just "ApplicationUrl") is used whenever application code needs to build a URL pointing back to the site. For example, when a user resets their password and t…

An issue was discovered in Squid through 4.13 and 5.x through 5.0.4. Due to improper input validation, it allows a trusted client to perform HTTP Request Smuggling and access services otherwise forbidden by the security controls. This occu…

An exploitable vulnerability exists in the REST parser of video-core's HTTP server of the Samsung SmartThings Hub STH-ETH-250 - Firmware version 0.20.17. The video-core process incorrectly handles pipelined HTTP requests, which allows succ…

BIND 9.11.0 -> 9.11.36 9.12.0 -> 9.16.26 9.17.0 -> 9.18.0 BIND Supported Preview Editions: 9.11.4-S1 -> 9.11.36-S1 9.16.8-S1 -> 9.16.26-S1 Versions of BIND 9 earlier than those shown - back to 9.1.0, including Supported Preview Editions - …

A client may issue specially crafted HTTP/1.1 chunked requests to a Jetty server that cause Jetty and an intermediary proxy to interpret different request boundaries, potentially resulting in HTTP request smuggling. This is caused by J…

httpd function check_header/3 rejects duplicate Content-Length (per CVE-2026-23941) but never checks for the TE+CL co-presence that RFC 9112 §6.3 identifies as a probable smuggling attempt. handle_body/3 frames by chunked and silently dis…

Gracefulness code ignored cases that should be rejected, resulting in possible HTTP Request Smuggling opportunities. This issue affects OTP from OTP 22.2 before OTP 27.3.4.17, from OTP 28.0 before OTP 28.5.0.6, and from OTP 29.0 befo…

httpd has never implemented obs-fold (RFC 2616 §2.2 / RFC 7230 §3.2.4 header continuation lines). Every CRLF followed by a non-CRLF octet unconditionally starts a new header. This missing feature became a security concern as the understa…

Apache Traffic Server forwards HTTP/2 origin trailers to HTTP/1 clients without proper chunked framing when converting HTTP/2 to HTTP/1. This issue affects Apache Traffic Server: from 10.0.0 through 10.1.3. Users are recommended to upgra…

Twisted is an event-based framework for internet applications, supporting Python 3.6+. The HTTP 1.0 and 1.1 server provided by twisted.web could process pipelined HTTP requests out-of-order, possibly resulting in information disclosure. Th…

Apache Tomcat 10.0.0-M1 to 10.0.6, 9.0.0.M1 to 9.0.46 and 8.5.0 to 8.5.66 did not correctly parse the HTTP transfer-encoding request header in some circumstances leading to the possibility to request smuggling when used with a reverse prox…

A flaw was found in Netty. A remote unauthenticated attacker can exploit a vulnerability in Netty's HTTP/1 to HTTP/2 conversion process. When an HTTP/1 request includes both an absolute-form request-target and a conflicting Host header, Ne…

Skipper is an HTTP router and reverse proxy for service composition. Prior to 0.27.35, the opaAuthorizeRequestWithBody filter in filters/openpolicyagent/openpolicyagent.go can allow an oversized declared Content-Length request to bypass a …

Traefik is an open source HTTP reverse proxy and load balancer. Prior to 2.11.57, and 3.7.13, Traefik accepts a rootless HTTP/1 request target that Go stores in URL.Opaque while leaving URL.Path empty. The rewriteRequestBuilder path evalua…

Inconsistent interpretation of http requests ('http request/response smuggling') in Visual Studio Code allows an unauthorized attacker to bypass a security feature over a network.

HCL BigFix Service Management is susceptible to HTTP Request Smuggling.  HTTP request smuggling vulnerabilities arise when websites route HTTP requests through web servers with inconsistent HTTP parsing. HTTP Smuggling exploits inconsiste…

A flaw in libsoup’s HTTP header handling allows multiple Host: headers in a request and returns the last occurrence for server-side processing. Common front proxies often honor the first Host: header, so this mismatch can cause vhost con…

Envoy is an open source edge and service proxy designed for cloud-native applications. Envoy allows mixed-case schemes in HTTP/2, however, some internal scheme checks are case-sensitive. Prior to versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, a…

Gunicorn fails to properly validate Transfer-Encoding headers, leading to HTTP Request Smuggling (HRS) vulnerabilities. By crafting requests with conflicting Transfer-Encoding headers, attackers can bypass security restrictions and access …

Apache HTTP Server versions 2.4.20 to 2.4.43 When trace/debug was enabled for the HTTP/2 module and on certain traffic edge patterns, logging statements were made on the wrong connection, causing concurrent use of memory pools. Configuring…