CWE-444— Inconsistent Interpretation of HTTP Requests (HTTP Request Smuggling)
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.— MITRE CWE catalog
484 active CVEs classified under this weakness category. Sourced from NVD, GHSA, and vendor advisories. Full definition on MITRE →
CVEs classified under CWE-444page 8 of 10
- CVE-2026-39805MEDIUMCVSS 6.3EG 6.32026-05-01
Inconsistent Interpretation of HTTP Requests vulnerability in mtrudel bandit allows HTTP request smuggling via duplicate Content-Length headers. 'Elixir.Bandit.Headers':get_content_length/1 in lib/bandit/headers.ex uses List.keyfind/3, wh…
- CVE-2025-12874MEDIUMCVSS 6.3EG 6.32025-12-19
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in Quest Coexistence Manager for Notes (Free/Busy Connector modules) allows HTTP Request Smuggling via the Content-Length-Transfer-Encoding (CL.…
- CVE-2016-15039MEDIUMCVSS 6.3EG 6.32024-07-11
A vulnerability classified as critical was found in mhuertos phpLDAPadmin up to 665dbc2690ebeb5392d38f1fece0a654225a0b38. Affected by this vulnerability is the function makeHttpRequest of the file htdocs/js/ajax_functions.js. The manipulat…
- CVE-2024-32638MEDIUMCVSS 6.3EG 6.32024-05-02
Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling') vulnerability in Apache APISIX when using `forward-auth` plugin.This issue affects Apache APISIX: from 3.8.0, 3.9.0. Users are recommended to upgrade to version 3.8.…
- CVE-2024-24795MEDIUMCVSS 6.3EG 6.32024-04-04
HTTP Response splitting in multiple modules in Apache HTTP Server allows an attacker that can inject malicious response headers into backend applications to cause an HTTP desynchronization attack. Users are recommended to upgrade to versi…
- CVE-2026-55087MEDIUMCVSS 6.1EG 6.12026-08-13
Etherpad is a real-time collaborative editor. From 2.1.0 until 3.1.0, Etherpad uses the attacker-controlled x-proxy-path request header in src/node/hooks/express/admin.ts when substituting paths into HTML, JavaScript, and CSS under /admin …
- CVE-2026-72587MEDIUMCVSS 6.1EG 6.12026-08-10
A cache poisoning vulnerability in CoreBunch/Instatic through 0.0.14 allows an unauthenticated remote attacker to poison the shared process-wide render cache by manipulating the u query parameter of the GET /_instatic/hole/<nodeId> server …
- CVE-2025-4366MEDIUMCVSS 6.1EG 6.12025-05-22
A request smuggling vulnerability identified within Pingora’s proxying framework, pingora-proxy, allows malicious HTTP requests to be injected via manipulated request bodies on cache HITs, leading to unauthorized request execution and po…
- CVE-2022-38114MEDIUMCVSS 6.1EG 6.12022-11-23
This vulnerability occurs when a web server fails to correctly process the Content-Length of POST requests. This can lead to HTTP request smuggling or XSS.
- CVE-2022-20713MEDIUMCVSS 6.1EG 6.12022-08-10
A vulnerability in the VPN web client services component of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to conduct browser-based attacks…
- CVE-2020-7658MEDIUMCVSS 6.1EG 6.12020-05-22
meinheld prior to 1.0.2 is vulnerable to HTTP Request Smuggling. HTTP pipelining issues and request smuggling attacks might be possible due to incorrect Content-Length and Transfer encoding header parsing.
- CVE-2020-7655MEDIUMCVSS 6.1EG 6.12020-05-21
netius prior to 1.17.58 is vulnerable to HTTP Request Smuggling. HTTP pipelining issues and request smuggling attacks might be possible due to incorrect Transfer encoding header parsing which could allow for CL:TE or TE:TE attacks.
- CVE-2018-7068MEDIUMCVSS 6.1EG 6.12018-08-06
HPE has identified a remote HOST header attack vulnerability in HPE CentralView Fraud Risk Management earlier than version CV 6.1. This issue is resolved in HF16 for HPE CV 6.1 or subsequent version.
- CVE-2017-7559MEDIUMCVSS 6.1EG 6.12018-01-10
In Undertow 2.x before 2.0.0.Alpha2, 1.4.x before 1.4.17.Final, and 1.3.x before 1.3.31.Final, it was found that the fix for CVE-2017-2666 was incomplete and invalid characters are still allowed in the query string and path parameters. Thi…
- CVE-2026-102479MEDIUMCVSS 5.9EG 5.92026-10-14
In Eclipse Vert.x versions [5.0.0,5.0.12] or [5.1.0,5.1.9] or [5.2.0, 5.2.0], the Vert.x HTTP/1.x decoder uses a canonicalization for well known HTTP headers, the canonicalization process interprets well crafted headers as headers of this …
- CVE-2026-84363MEDIUMCVSS 5.9EG 5.92026-09-01
Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.13.5, Hono's query helpers treat a question mark after a literal hash fragment as the start of a query string, so the application can read req…
- CVE-2026-78605MEDIUMCVSS 5.9EG 5.92026-09-01
Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling') (CWE-444) in Elasticsearch can lead to information disclosure via HTTP Request Smuggling (CAPEC-33). Under specific proxy deployment configurations, a network attacker…
- CVE-2026-62899MEDIUMCVSS 5.9EG 5.92026-08-11
Inconsistent interpretation of http requests ('http request/response smuggling') in .NET allows an unauthorized attacker to bypass a security feature over a network.
- CVE-2024-34535MEDIUMCVSS 5.9EG 5.92024-10-03
In Mastodon 4.1.6, API endpoint rate limiting can be bypassed by setting a crafted HTTP request header.
- CVE-2024-22279MEDIUMCVSS 5.9EG 5.92024-06-10
Improper handling of requests in Routing Release > v0.273.0 and <= v0.297.0 allows an unauthenticated attacker to degrade the service availability of the Cloud Foundry deployment if performed at scale.
- CVE-2024-23326MEDIUMCVSS 5.9EG 5.92024-06-04
Envoy is a cloud-native, open source edge and service proxy. A theoretical request smuggling vulnerability exists through Envoy if a server can be tricked into adding an upgrade header into a response. Per RFC https://www.rfc-editor.org/rf…
- CVE-2022-0552MEDIUMCVSS 5.9EG 5.92022-04-11
A flaw was found in the original fix for the netty-codec-http CVE-2021-21409, where the OpenShift Logging openshift-logging/elasticsearch6-rhel8 container was incomplete. The vulnerable netty-codec-http maven package was not removed from t…
- CVE-2021-21409MEDIUMCVSS 5.9EG 5.92021-03-30
Netty is an open-source, asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. In Netty (io.netty:netty-codec-http2) before version 4.1.61.Final there is …
- CVE-2021-21295MEDIUMCVSS 5.9EG 5.92021-03-09
Netty is an open-source, asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. In Netty (io.netty:netty-codec-http2) before version 4.1.60.Final there is …
- CVE-2020-7764MEDIUMCVSS 5.9EG 5.92020-11-08
This affects the package find-my-way before 2.2.5, from 3.0.0 and before 3.0.5. It accepts the Accept-Version' header by default, and if versioned routes are not being used, this could lead to a denial of service. Accept-Version can be use…
- CVE-2019-19326MEDIUMCVSS 5.9EG 5.92020-07-15
Silverstripe CMS sites through 4.4.4 which have opted into HTTP Cache Headers on responses served by the framework's HTTP layer can be vulnerable to web cache poisoning. Through modifying the X-Original-Url and X-HTTP-Method-Override heade…
- CVE-2025-55018MEDIUMCVSS 5.8EG 5.82026-02-10
An inconsistent interpretation of http requests ('http request smuggling') vulnerability in Fortinet FortiOS 7.6.0, FortiOS 7.4.0 through 7.4.9, FortiOS 7.2 all versions, FortiOS 7.0 all versions, FortiOS 6.4.3 through 6.4.16 may allow an…
- CVE-2023-38697MEDIUMCVSS 5.8EG 5.82023-08-04
protocol-http1 provides a low-level implementation of the HTTP/1 protocol. RFC 9112 Section 7.1 defined the format of chunk size, chunk data and chunk extension. The value of Content-Length header should be a string of 0-9 digits, the chun…
- CVE-2026-84380MEDIUMCVSS 5.6EG 5.62026-09-02
HTTPX2 is a next generation HTTP client for Python. Prior to 2.11.0, Request._prepare() in src/httpx2/httpx2/_models.py can add a body-derived Content-Length header to a request that already contains a caller-supplied Transfer-Encoding hea…
- CVE-2026-58047MEDIUMCVSS 5.6EG 5.62026-07-31
HTTP Smuggling in cPanel allows potential leak of credentials.
- CVE-2026-115877MEDIUMCVSS 5.4EG 5.42026-10-23
Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to 26.10.0rc1, twisted.web.http.HTTPChannel.headerReceived rejects a NUL byte in an HTTP header value but accepts a bare carriage return or bare l…
- CVE-2026-100724MEDIUMCVSS 5.4EG 5.42026-09-27
http4k (Maven package org.http4k:http4k-core) before 6.49.0.0, 5.42.0.0 and 4.51.0.0 uses substring (Contains) matching on the Host header by default in reverseProxy() and reverseProxyRouting() when dispatching to configured virtual hosts.…
- CVE-2026-69216MEDIUMCVSS 5.4EG 5.42026-09-15
Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, Ember’s chunk decoder trims the chunk-size token and accepts leading plus or minus signs instead of requiring one or more hexadecimal digits followed by the r…
- CVE-2026-67181MEDIUMCVSS 5.4EG 5.42026-07-28
Rouille 0.3.3 through 3.6.2 contains an HTTP request smuggling vulnerability that allows remote attackers to desynchronize HTTP message boundaries by exploiting improper header forwarding in the proxy implementation. The proxy in src/proxy…
- CVE-2026-66752MEDIUMCVSS 5.4EG 5.42026-07-28
tiny-http through 0.12.0 contains an HTTP request smuggling vulnerability that allows remote attackers to desynchronize request framing by sending a Transfer-Encoding header with any value, including non-chunked codings, which causes the l…
- CVE-2026-58055MEDIUMCVSS 5.4EG 5.42026-06-28
nghttp2's nghttpx proxy through 1.69.0 forwards an HTTP/1.1 Upgrade request that also carries a Content-Length header and body onto reusable keep-alive backend connections, re-adding the Upgrade and Connection headers while passing Content…
- CVE-2026-46342MEDIUMCVSS 5.4EG 5.42026-05-19
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_i…
- CVE-2025-47905MEDIUMCVSS 5.4EG 5.42025-05-13
Varnish Cache before 7.6.3 and 7.7 before 7.7.1, and Varnish Enterprise before 6.0.13r14, allow client-side desync via HTTP/1 requests, because the product incorrectly permits CRLF to be skipped to delimit chunk boundaries.
- CVE-2025-30346MEDIUMCVSS 5.4EG 5.42025-03-21
Varnish Cache before 7.6.2 and Varnish Enterprise before 6.0.13r10 allow client-side desync via HTTP/1 requests.
- CVE-2024-45614MEDIUMCVSS 5.4EG 5.42024-09-19
Puma is a Ruby/Rack web server built for parallelism. In affected versions clients could clobber values set by intermediate proxies (such as X-Forwarded-For) by providing a underscore version of the same header (X-Forwarded_For). Any users…
- CVE-2023-30910MEDIUMCVSS 5.4EG 5.42023-10-09
HPE MSA Controller prior to version IN210R004 could be remotely exploited to allow inconsistent interpretation of HTTP requests.
- CVE-2023-27491MEDIUMCVSS 5.4EG 5.42023-04-04
Envoy is an open source edge and service proxy designed for cloud-native applications. Compliant HTTP/1 service should reject malformed request lines. Prior to versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, There is a possibility tha…
- CVE-2021-34559MEDIUMCVSS 5.4EG 5.42021-08-31
In PEPPERL+FUCHS WirelessHART-Gateway <= 3.0.8 a vulnerability may allow remote attackers to rewrite links and URLs in cached pages to arbitrary strings.
- CVE-2021-21445MEDIUMCVSS 5.4EG 5.42021-01-12
SAP Commerce Cloud, versions - 1808, 1811, 1905, 2005, 2011, allows an authenticated attacker to include invalidated data in the HTTP response Content Type header, due to improper input validation, and sent to a Web user. A successful expl…
- CVE-2020-28361MEDIUMCVSS 5.4EG 5.42020-11-18
Kamailio before 5.4.0, as used in Sip Express Router (SER) in Sippy Softswitch 4.5 through 5.2 and other products, allows a bypass of a header-removal protection mechanism via whitespace characters. This occurs in the remove_hf function in…
- CVE-2020-10112MEDIUMCVSS 5.4EG 5.42020-03-06
Citrix Gateway 11.1, 12.0, and 12.1 allows Cache Poisoning. NOTE: Citrix disputes this as not a vulnerability. By default, Citrix ADC only caches static content served under certain URL paths for Citrix Gateway usage. No dynamic content is…
- CVE-2020-5207MEDIUMCVSS 5.4EG 5.42020-01-27
In Ktor before 1.3.0, request smuggling is possible when running behind a proxy that doesn't handle Content-Length and Transfer-Encoding properly or doesn't handle \n as a headers separator.
- CVE-2017-12158MEDIUMCVSS 5.4EG 5.42017-10-26
It was found that Keycloak would accept a HOST header URL in the admin console and use it to determine web resource locations. An attacker could use this flaw against an authenticated user to attain reflected XSS via a malicious server.
- CVE-2026-121439MEDIUMCVSS 5.3EG 5.32026-11-03
Wasmtime 46.0.0 before 48.0.7 and 49.0.0 before 49.0.4 contains a response splitting vulnerability in wasi-http p3 that allows guests to set unvalidated content-length headers. Malicious wasip3 guests can splice an existing body into a new…
- CVE-2026-103399MEDIUMCVSS 5.3EG 5.32026-09-30
A flaw was found in SoupServer (libsoup). When an HTTP/1.x client sends a request with Expect: 100-continue and a request body, and SoupServer returns an early final (non-1xx) response before the body is read, the server neither drains the…
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