Weakness (CWE)
CWE-444: Inconsistent Interpretation of HTTP Requests
The product acts as an intermediary HTTP agent
(such as a proxy or firewall) in the data flow between two
entities such as a client and server, but it does not
interpret malformed HTTP requests or responses in ways that
are consistent with how the messages will be processed by
those entities that are at the ultimate destination.
More detail
HTTP requests or responses ("messages") can be
malformed or unexpected in ways that cause web servers or
clients to interpret the messages in different ways than
intermediary HTTP agents such as load balancers, reverse
proxies, web caching proxies, application firewalls,
etc. For example, an adversary may be able to add duplicate
or different header fields that a client or server might
interpret as one set of messages, whereas the intermediary
might interpret the same sequence of bytes as a different
set of messages. For example, discrepancies can arise in
how to handle duplicate headers like two Transfer-encoding
(TE) or two Content-length (CL), or the malicious HTTP
message will have different headers for TE and
CL.
The inconsistent parsing and interpretation of messages
can allow the adversary to "smuggle" a message to the
client/server without the intermediary being aware of it.
This weakness is usually the result of the usage
of outdated or incompatible HTTP protocol versions in the
HTTP agents.
How to prevent it (4 mitigations)
-
Implementation
Use a web server that employs a strict HTTP parsing procedure, such as Apache [REF-433].
-
Implementation
Use only SSL communication.
-
Implementation
Terminate the client session after each request.
-
System Configuration
Turn all pages to non-cacheable.
Source: MITRE CWE-444
25 results · Clear filters · Feed
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Low 2.9
Caddy: RFC 7230 §6.1 compliance issue / Hop-by-hop headers that leak through
Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.5, the reverse proxy's finalizeResponse method in modules/caddyhttp/reverseproxy/reverseproxy.go handles an upstream 101 Switching Protocols response before running removeConnectio…
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Low 3.7
Wasmtime before 36.0.19, 37.0.0 before 48.0.7, and 49.0.0 before 49.0.4 wasi-http Request Smuggling
Wasmtime before 36.0.19, 37.0.0 before 48.0.7, and 49.0.0 before 49.0.4 contains a request smuggling vulnerability in wasi-http that allows guests to set multiple conflicting content-length headers. Malicious guests can make the host send HTTP requests with c…
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Low 3.7
uhttpd vulnerable to HTTP request smuggling via invalid chunk-length state reset
uhttpd is a small HTTP server. In unpatched repository snapshots, `client_poll_post_data()` in `client.c` consumes an invalid chunk-length line, such as a size exceeding INT_MAX, then clears `r->content_length` and `r->transfer_chunked` without draining the r…
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Low 2.0
Lenient parsing of integers for response body and chunk framing
Response body and chunk parsing would handle non-hex or negative integers incorrectly which could result in misinterpreting HTTP response contents.
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Low 3.6
Front-end Desynchronization Vulnerability in Progress® Telerik® Fiddler® Classic
In Progress® Telerik® Fiddler® Classic for Windows, versions prior to v6.0.20262.10021, front-end request desynchronization is possible in the proxy request forwarding component. A request that contains both a Content-Length and a Transfer-Encoding header is …
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Low 3.7
Apache Tomcat: Transfer-Encoding honored for HTTP/1.0 requests
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in Apache Tomcat caused by processing the transfer-encoding header for an HTTP/1.0 request may allow an attacker to cause one request from another user to fail when…
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Low 3.7
undici vulnerable to downstream response splitting via retry interceptor
undici's retry interceptor can append the body of a ranged retry response to bytes already delivered from an earlier partial response while still presenting the original response's status and headers. This happens when an upstream server delivers part of a bo…
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Low 3.7
A flaw in Node.js HTTP client can cause a request desynchronization for Node.js-based forwarding proxies that rebuild o…
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Low 3.7CVE-2026-58044 Public exploit
A flaw in Node.js HTTP client can cause a request desynchronization for Node.js-based forwarding proxies that rebuild o…
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Low 3.7
Python-Multipart: Semicolon treated as querystring field separator enables parameter smuggling
Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.30, QuerystringParser treated ; as a field separator in application/x-www-form-urlencoded bodies, in addition to &. The WHATWG URL standard, modern browsers, and Python's urllib.parse (…
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Low 2.3
Nuxt: `__nuxt_island` endpoint does not bind responses to request props, enabling shared-cache poisoning
Nuxt is an open-source web development framework for Vue.js. In Nuxt versions 3.1.0 to before 3.21.6 and 4.0.0-alpha.1 to before 4.4.6 and @nuxt/nitro-server versions 3.20.0 to before 3.21.6 and 4.0.0-alpha.1 to before 4.4.6, the /__nuxt_island/* endpoint acc…
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Low 3.7
Header injection via WebSocket upgrade parser differential allows ASGI scope header spoofing
daphne before 4.2.2 reconstructs a raw HTTP request from Twisted's parsed headers and feeds it to autobahn for WebSocket handshake processing. Twisted does not treat \x0b, \x0c, \x1c, \x1d, \x1e, or \x85 as header line separators, but autobahn decodes header …
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Low 2.3
In Vinyl Cache before 9.0.1 and Varnish Cache before 9.0.3, a deficiency in HTTP/2 request parsing can be exploited to …
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Low 3.7
Libsoup: libsoup: http request smuggling via duplicate content-length headers
A request smuggling vulnerability exists in libsoup's HTTP/1 header parsing logic. The soup_message_headers_append_common() function in libsoup/soup-message-headers.c unconditionally appends each header value without validating for duplicate or conflicting Co…
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Low 3.7
HCL BigFix Service Management (SM) is susceptible to HTTP Request Smuggling
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 inconsistencies in request pars…
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Low 2.9
HTTP Request Smuggling in visualfc/liteide
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in visualfc liteide (liteidex/src/3rdparty/qjsonrpc/src/http-parser modules). This vulnerability is associated with program files http_parser.C. This issue affects …
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Low 2.7
AIOHTTP Regex Mismatch Allows Unicode in ASCII-Only Protocol Fields
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Versions 3.13.2 and below contain parser logic which allows non-ASCII decimals to be present in the Range header. There is no known impact, but there is the possibility that there…
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Low 2.9
Netty is vulnerable to request smuggling due to incorrect parsing of chunk extensions
Netty is an asynchronous event-driven network application framework for development of maintainable high performance protocol servers and clients. In versions 4.1.124.Final, and 4.2.0.Alpha3 through 4.2.4.Final, Netty incorrectly accepts standalone newline ch…
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Low 1.7
AIOHTTP is vulnerable to HTTP Request/Response Smuggling through incorrect parsing of chunked trailer sections
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.12.14, the Python parser is vulnerable to a request smuggling vulnerability due to not parsing trailer sections of an HTTP request. If a pure Python version of …
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Low 3.7
Next.js cache poisoning due to omission of Vary header
Next.js is a React framework for building full-stack web applications. In Next.js App Router from 15.3.0 to before 15.3.3 and Vercel CLI from 41.4.1 to 42.2.0, a cache poisoning vulnerability was found. The issue allowed page requests for HTML content to retu…
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Low 3.1
Erroneous parsing of multipart form data
In PHP versions 8.1.* before 8.1.30, 8.2.* before 8.2.24, 8.3.* before 8.3.12, erroneous parsing of multipart form data contained in an HTTP POST request could lead to legitimate data not being processed. This could lead to malicious attacker able to control …
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Low 3.4
Inconsistent interpretation of `Content-Length` vs. `Transfer-Encoding` in aiohttp
aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. Affected versions of aiohttp have a security vulnerability regarding the inconsistent interpretation of the http protocol. HTTP/1.1 is a persistent protocol, if both Content-Lengt…
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Low 3.7
Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling') in puma
Puma is a HTTP 1.1 server for Ruby/Rack applications. Prior to versions 5.5.1 and 4.3.9, using `puma` with a proxy which forwards HTTP header values which contain the LF character could allow HTTP request smugggling. A client could smuggle a request through a…
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Low 3.1
Lenient Parsing of Content-Length Header When Prefixed with Plus Sign
hyper is an HTTP library for rust. hyper's HTTP/1 server code had a flaw that incorrectly parses and accepts requests with a `Content-Length` header with a prefixed plus sign, when it should have been rejected as illegal. This combined with an upstream HTTP p…
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Low 2.6
Undertow Request Smuggling vulnerability
It was discovered that Undertow before 1.4.17, 1.3.31 and 2.0.0 processes http request headers with unusual whitespaces which can cause possible http request smuggling.