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 4 of 10
- CVE-2026-15328HIGHCVSS 8.1EG 8.12026-07-28
IBM WebSphere Application Server and IBM WebSphere Application Server - Liberty is vulnerable to HTTP request smuggling.
- CVE-2026-52845HIGHCVSS 8.1EG 8.12026-06-16
Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, forward_auth copy_headers deletes the exact client-supplied identity header before copying the trusted value from the auth gateway. But when the request late…
- CVE-2023-27493HIGHCVSS 8.1EG 8.12023-04-04
Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, Envoy does not sanitize or escape request properties when generating request headers. This…
- CVE-2022-24801HIGHCVSS 8.1EG 8.12022-04-04
Twisted is an event-based framework for internet applications, supporting Python 3.6+. Prior to version 22.4.0rc1, the Twisted Web HTTP 1.1 server, located in the `twisted.web.http` module, parsed several HTTP request constructs more lenie…
- CVE-2021-29991HIGHCVSS 8.1EG 8.12021-11-03
Firefox incorrectly accepted a newline in a HTTP/3 header, interpretting it as two separate headers. This allowed for a header splitting attack against servers using HTTP/3. This vulnerability affects Firefox < 91.0.1 and Thunderbird < 91.…
- CVE-2021-39214HIGHCVSS 8.1EG 8.12021-09-16
mitmproxy is an interactive, SSL/TLS-capable intercepting proxy. In mitmproxy 7.0.2 and below, a malicious client or server is able to perform HTTP request smuggling attacks through mitmproxy. This means that a malicious client/server coul…
- CVE-2017-8894HIGHCVSS 8.1EG 8.12017-07-02
AeroAdmin 4.1 uses an insecure protocol (HTTP) to perform software updates. An attacker can hijack an update via man-in-the-middle in order to execute code in the machine.
- CVE-2026-61642HIGHCVSS 7.7EG 7.72026-10-13
Squid is a caching proxy for the Web. From 3.3.0.1 to before 7.6, due to an improper enforcement of behavioral workflow bug, Squid is vulnerable to a Request Smuggling attack against HTTP/1.1 Transfer-Encoding. HTTP header parsing (`src/Ht…
- CVE-2024-33452HIGHCVSS 7.7EG 7.72025-04-22
An issue in OpenResty lua-nginx-module v.0.10.26 and before allows a remote attacker to conduct HTTP request smuggling via a crafted HEAD request.
- CVE-2026-112212HIGHCVSS 7.5EG 7.52026-10-21
GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.3 before 19.3.6, 19.4 before 19.4.3, and 19.5 before 19.5.1 that, under certain conditions, an unauthenticated user could have poisoned a shared cache's OAuth/OI…
- CVE-2026-86146HIGHCVSS 7.5EG 7.52026-10-21
Inconsistent interpretation of HTTP requests (HTTP request/response smuggling) in the bundled HTTP/1.1 parser of Apache bRPC (version < 1.18.0) on all platforms allows remote attackers to smuggle requests and inject headers when bRPC is de…
- CVE-2026-94439HIGHCVSS 7.5EG 7.52026-10-08
When an HTTP server handler sends a 2xx response to an HTTP/1 CONNECT request and returns without hijacking the connection, the server improperly continues to read and serve requests from the connection. Since a 2xx response to an HTTP/1 C…
- CVE-2026-78660HIGHCVSS 7.5EG 7.52026-10-08
Historically, we have been rather lax about malformed framing-related headers in our HTTP/2 implementation, as they cannot interfere with HTTP/2 framing. However, this makes it possible for our HTTP/2 implementation to forward responses co…
- CVE-2026-56866HIGHCVSS 7.5EG 7.52026-10-08
When http.Transport sends an HTTP/1 CONNECT request with a non-empty Request.Body, it writes the body directly to the connection without framing after the request headers. If the server rejects the CONNECT request with a non-2xx keep-alive…
- CVE-2026-63718HIGHCVSS 7.5EG 7.52026-10-01
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') response smuggling vulnerability in Apache HTTP Server via mod_proxy_uwsgi and a crafted uwsgi response with Transfer-Encoding. This issue affects Apache H…
- CVE-2026-73548HIGHCVSS 7.5EG 7.52026-09-21
Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy forwards data for a configured non-WebSocket HTTP upgrade before the upstream accepts the upgrade. A…
- CVE-2024-14029HIGHCVSS 7.5EG 7.52026-09-15
Tornado before 6.4.1 ignores duplicate Transfer-Encoding: chunked headers, treating requests as having no message body and parsing the chunked body as a subsequent request. Attackers can exploit this inconsistency when Tornado is deployed …
- CVE-2023-54397HIGHCVSS 7.5EG 7.52026-09-15
Tornado before 6.3.3 contains an HTTP request smuggling vulnerability due to improper parsing of Content-Length headers accepting non-standard characters. Attackers can send crafted HTTP requests with these characters to bypass proxy valid…
- CVE-2026-74848HIGHCVSS 7.5EG 7.52026-08-27
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in Apache APISIX. An attacker could make other clients receive attacker-chosen or other users' responses on serverless-plugin routes. This …
- CVE-2026-65370HIGHCVSS 7.5EG 7.52026-08-12
ServiceTalk HTTP/1.x incorrectly handles malformed Transfer-Encoding which could result in request smuggling attacks. This vulnerability is addressed in servicetalk version 0.42.65.
- CVE-2026-67182HIGHCVSS 7.5EG 7.52026-07-28
Rouille 0.3.3 through 3.6.2 contains an HTTP request smuggling vulnerability that allows remote attackers to bypass access controls by injecting bare line feed characters (0x0A) into client-supplied request header values that are copied ve…
- CVE-2026-59898HIGHCVSS 7.5EG 7.52026-07-22
Netty is an asynchronous, event-driven network application framework. Prior to versions 4.1.136.Final and 4.2.16.Final, ab attacker can force WebSocket upgrade via the lax V07 (or V08) handshaker by sending `Sec-WebSocket-Version: 7` and …
- CVE-2025-3110HIGHCVSS 7.5EG 7.52026-07-08
OpenVPN Access Server 2.7.2 through 3.1.0 accepts bare line-feed sequences inside HTTP header values, allowing remote attackers to perform HTTP request smuggling when deployed behind a reverse proxy
- CVE-2026-11806HIGHCVSS 7.5EG 7.52026-06-30
IBM WebSphere Application Server - Liberty 17.0.0.3 through 26.0.0.6 is affected by an arbitrary file read vulnerability with the restConnector-2.0 feature enabled.
- CVE-2026-48743HIGHCVSS 7.5EG 7.52026-06-26
Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.35.11, 1.36.7, 1.37.3, and 1.38.1, Envoy can translate a downstream HTTP/3 request that is complete at the transport layer (HEADERS with FIN …
- CVE-2026-48979HIGHCVSS 7.5EG 7.52026-06-17
PHP Standard Library (PSL) is set of APIs covering async, collections, networking, I/O, cryptography, terminal UI, etc. In versions 6.1.0, 6.1.1 and 6.2.0, the Psl\H2\ServerConnection does not validate that the total bytes received in DATA…
- CVE-2026-8620HIGHCVSS 7.5EG 7.52026-05-26
IBM Web Server Plug-ins for WebSphere Application Server and WebSphere Liberty 8.5, 9.0 IBM WebSphere Application Server and WebSphere Application Server Liberty are vulnerable to HTTP request smuggling in the Web Server Plug-ins through a…
- CVE-2026-42585HIGHCVSS 7.5EG 7.52026-05-13
Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty incorrectly parses malformed Transfer-Encoding, enabling request smuggling attacks. This vulnerability is fixed in 4.2.13.…
- CVE-2026-40562HIGHCVSS 7.5EG 7.52026-05-06
Gazelle versions through 0.49 for Perl allows HTTP Request Smuggling via Improper Header Precedence. Gazelle incorrectly prioritizes "Content-Length" over "Transfer-Encoding: chunked" when both headers are present in an HTTP request. Per …
- CVE-2026-40560HIGHCVSS 7.5EG 7.52026-04-29
Starman versions before 0.4018 for Perl allows HTTP Request Smuggling via Improper Header Precedence. Starman incorrectly prioritizes "Content-Length" over "Transfer-Encoding: chunked" when both headers are present in an HTTP request. Per…
- CVE-2026-24880HIGHCVSS 7.5EG 7.52026-04-09
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in Apache Tomcat via invalid chunk extension. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.18, from 10.1.0-M1 through 10.1.52,…
- CVE-2026-31842HIGHCVSS 7.5EG 7.52026-04-07
Tinyproxy through 1.11.3 is vulnerable to HTTP request parsing desynchronization due to a case-sensitive comparison of the Transfer-Encoding header in src/reqs.c. The is_chunked_transfer function uses strcmp to compare the header value aga…
- CVE-2025-65114HIGHCVSS 7.5EG 7.52026-04-02
Apache Traffic Server allows request smuggling if chunked messages are malformed. This issue affects Apache Traffic Server: from 9.0.0 through 9.2.12, from 10.0.0 through 10.1.1. Users are recommended to upgrade to version 9.2.13 or 10…
- CVE-2026-33870HIGHCVSS 7.5EG 7.52026-03-27
Netty is an asynchronous, event-driven network application framework. In versions prior to 4.1.132.Final and 4.2.10.Final, Netty incorrectly parses quoted strings in HTTP/1.1 chunked transfer encoding extension values, enabling request smu…
- CVE-2025-61258HIGHCVSS 7.5EG 7.52025-12-09
Outsystems Platform Server 11.18.1.37828 allows attackers to cause a denial of service via a crafted content-length value mismatching the body length. NOTE: the Supplier indicates that they are unable to reproduce this.
- CVE-2025-59822HIGHCVSS 7.5EG 7.52025-09-23
Http4s is a Scala interface for HTTP services. In versions from 1.0.0-M1 to before 1.0.0-M45 and before 0.23.31, http4s is vulnerable to HTTP Request Smuggling due to improper handling of HTTP trailer section. This vulnerability could enab…
- CVE-2025-58056HIGHCVSS 7.5EG 7.52025-09-03
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 s…
- CVE-2025-53643HIGHCVSS 7.5EG 7.52025-07-14
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 pur…
- CVE-2025-49826HIGHCVSS 7.5EG 7.52025-07-03
Next.js is a React framework for building full-stack web applications. From versions 15.0.4-canary.51 to before 15.1.8, a cache poisoning bug leading to a Denial of Service (DoS) condition was found in Next.js. This issue does not impact c…
- CVE-2025-4600HIGHCVSS 7.5EG 7.52025-05-16
A request smuggling vulnerability existed in the Google Cloud Classic Application Load Balancer due to improper handling of chunked-encoded HTTP requests. This allowed attackers to craft requests that could be misinterpreted by backend ser…
- CVE-2024-53868HIGHCVSS 7.5EG 7.52025-04-03
Apache Traffic Server allows request smuggling if chunked messages are malformed. This issue affects Apache Traffic Server: from 9.2.0 through 9.2.9, from 10.0.0 through 10.0.4. Users are recommended to upgrade to version 9.2.10 or…
- CVE-2025-31137HIGHCVSS 7.5EG 7.52025-04-01
React Router is a multi-strategy router for React bridging the gap from React 18 to React 19. There is a vulnerability in Remix/React Router that affects all Remix 2 and React Router 7 consumers using the Express adapter. Basically, this v…
- CVE-2024-6827HIGHCVSS 7.5EG 7.52025-03-20
Gunicorn version 21.2.0 does not properly validate the value of the 'Transfer-Encoding' header as specified in the RFC standards, which leads to the default fallback method of 'Content-Length,' making it vulnerable to TE.CL request smuggli…
- CVE-2024-52304HIGHCVSS 7.5EG 7.52024-11-18
aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.10.11, the Python parser parses newlines in chunk extensions incorrectly which can lead to request smuggling vulnerabilities under certain c…
- CVE-2024-52530HIGHCVSS 7.5EG 7.52024-11-11
GNOME libsoup before 3.6.0 allows HTTP request smuggling in some configurations because '\0' characters at the end of header names are ignored, i.e., a "Transfer-Encoding\0: chunked" header is treated the same as a "Transfer-Encoding: chun…
- CVE-2024-44775HIGHCVSS 7.5EG 7.52024-10-15
kmqtt v0.2.7 is vulnerable to Denial of Service (DoS) due to a Null Pointer Exception. A remote attacker can cause the broker to crash by sending a specially crafted MQTT CONNECT packet that triggers an unhandled null reference, leading to…
- CVE-2024-8912HIGHCVSS 7.5EG 7.52024-10-11
An HTTP Request Smuggling vulnerability in Looker allowed an unauthorized attacker to capture HTTP responses destined for legitimate users. There are two Looker versions that are hosted by Looker: * Looker (Google Cloud core) was foun…
- CVE-2023-38522HIGHCVSS 7.5EG 7.52024-07-26
Apache Traffic Server accepts characters that are not allowed for HTTP field names and forwards malformed requests to origin servers. This can be utilized for request smuggling and may also lead cache poisoning if the origin servers are vu…
- CVE-2024-34350HIGHCVSS 7.5EG 7.52024-05-14
Next.js is a React framework that can provide building blocks to create web applications. Prior to 13.5.1, an inconsistent interpretation of a crafted HTTP request meant that requests are treated as both a single request, and two separate …
- CVE-2024-21088HIGHCVSS 7.5EG 7.52024-04-16
Vulnerability in the Oracle Production Scheduling product of Oracle E-Business Suite (component: Import Utility). Supported versions that are affected are 12.2.4-12.2.12. Easily exploitable vulnerability allows unauthenticated attacker wi…
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