← Back
CWE-444

356 CVEs • Abstraction: Base

Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response 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.

JSON object

Loading...

CVEs (356)

CVE
VENDORS
PRODUCTS
UPDATED
PUBLISHED
CVSS
2Apache
Debian
2Debian Linux
Traffic Server
Jun 17, 2026
Nov 3, 2021
N/A· v4
7.5 HIGH· v3
5.0 MEDIUM· v2
Improper input validation vulnerability in header parsing of Apache Traffic Server allows an attacker to smuggle requests. This issue affects Apache Traffic Server 8.0.0 to 8.1.2 and 9.0.0 to 9.1.0.
1Mozilla
2Firefox
Thunderbird
Jun 17, 2026
Nov 3, 2021
N/A· v4
8.1 HIGH· v3
5.8 MEDIUM· v2
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 an...Show more
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 < 91.0.1.Show less
2Debian
Puma
2Debian Linux
Puma
Jun 17, 2026
Oct 12, 2021
N/A· v4
3.7 LOW· v3
3.6 LOW· v2
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 c...Show more
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 proxy, causing the proxy to send a response back to another unknown client. The only proxy which has this behavior, as far as the Puma team is aware of, is Apache Traffic Server. If the proxy uses persistent connections and the client adds another request in via HTTP pipelining, the proxy may mistake it as the first request's body. Puma, however, would see it as two requests, and when processing the second request, send back a response that the proxy does not expect. If the proxy has reused the persistent connection to Puma to send another request for a different client, the second response from the first client will be sent to the second client. This vulnerability was patched in Puma 5.5.1 and 4.3.9. As a workaround, do not use Apache Traffic Server with `puma`.Show less
1Zeek
1Zeek
Jun 17, 2026
Sep 29, 2021
N/A· v4
7.5 HIGH· v3
5.0 MEDIUM· v2
An issue was discovered in zeek version 4.1.0. There is a HTTP request splitting vulnerability that will invalidate any ZEEK HTTP based security analysis. NOTE: the vendor's position is that the observed behavior is inte...Show more
An issue was discovered in zeek version 4.1.0. There is a HTTP request splitting vulnerability that will invalidate any ZEEK HTTP based security analysis. NOTE: the vendor's position is that the observed behavior is intendedShow less
1Pingidentity
1Pingaccess
Jun 17, 2026
Sep 24, 2021
N/A· v4
5.3 MEDIUM· v3
5.0 MEDIUM· v2
Ping Identity PingAccess before 5.3.3 allows HTTP request smuggling via header manipulation.
1Mitmproxy
1Mitmproxy
Jun 17, 2026
Sep 16, 2021
N/A· v4
9.8 CRITICAL· v3
7.5 HIGH· v2
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...Show more
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 could smuggle a request/response through mitmproxy as part of another request/response's HTTP message body. While a smuggled request is still captured as part of another request's body, it does not appear in the request list and does not go through the usual mitmproxy event hooks, where users may have implemented custom access control checks or input sanitization. Unless one uses mitmproxy to protect an HTTP/1 service, no action is required. The vulnerability has been fixed in mitmproxy 7.0.3 and above.Show less
1Sap
1Web Dispatcher
Jun 17, 2026
Sep 14, 2021
N/A· v4
9.4 CRITICAL· v3
7.5 HIGH· v2
SAP Web Dispatcher versions - 7.49, 7.53, 7.77, 7.81, KRNL64NUC - 7.22, 7.22EXT, 7.49, KRNL64UC -7.22, 7.22EXT, 7.49, 7.53, KERNEL - 7.22, 7.49, 7.53, 7.77, 7.81, 7.83 processes allow an unauthenticated attacker to submi...Show more
SAP Web Dispatcher versions - 7.49, 7.53, 7.77, 7.81, KRNL64NUC - 7.22, 7.22EXT, 7.49, KRNL64UC -7.22, 7.22EXT, 7.49, 7.53, KERNEL - 7.22, 7.49, 7.53, 7.77, 7.81, 7.83 processes allow an unauthenticated attacker to submit a malicious crafted request over a network to a front-end server which may, over several attempts, result in a back-end server confusing the boundaries of malicious and legitimate messages. This can result in the back-end server executing a malicious payload which can be used to read or modify any information on the server or consume server resources making it temporarily unavailable.Show less
1Pepperl Fuchs
2Wha Gw F2d2 0 As Z2 Eth.eip Firmware
Wha Gw F2d2 0 As Z2 Eth Firmware
Jun 17, 2026
Aug 31, 2021
N/A· v4
5.3 MEDIUM· v3
5.0 MEDIUM· v2
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.
1Linphone
1Belle Sip
Jun 17, 2026
Aug 12, 2021
N/A· v4
7.5 HIGH· v3
5.0 MEDIUM· v2
Belledonne Belle-sip before 4.5.20, as used in Linphone and other products, can crash via an invalid From header in a SIP message.
2Actix
Fedoraproject
2Actix Http
Fedora
Jun 17, 2026
Aug 10, 2021
N/A· v4
7.5 HIGH· v3
5.0 MEDIUM· v2
An issue was discovered in the actix-http crate before 3.0.0-beta.9 for Rust. HTTP/1 request smuggling (aka HRS) can occur, potentially leading to credential disclosure.
1Fortinet
2Fortianalyzer
Fortimanager
Jun 17, 2026
Aug 5, 2021
N/A· v4
4.3 MEDIUM· v3
4.0 MEDIUM· v2
An improper neutralization of CRLF sequences in HTTP headers ('HTTP Response Splitting') vulnerability In FortiManager and FortiAnalyzer GUI 7.0.0, 6.4.6 and below, 6.2.8 and below, 6.0.11 and below, 5.6.11 and below may...Show more
An improper neutralization of CRLF sequences in HTTP headers ('HTTP Response Splitting') vulnerability In FortiManager and FortiAnalyzer GUI 7.0.0, 6.4.6 and below, 6.2.8 and below, 6.0.11 and below, 5.6.11 and below may allow an authenticated and remote attacker to perform an HTTP request splitting attack which gives attackers control of the remaining headers and body of the response.Show less
5Debian
FedoraprojectVarnish Cache+2 more
5Debian Linux
FedoraVarnish Cache+2 more
Jun 17, 2026
Jul 14, 2021
N/A· v4
6.5 MEDIUM· v3
6.4 MEDIUM· v2
Varnish Cache, with HTTP/2 enabled, allows request smuggling and VCL authorization bypass via a large Content-Length header for a POST request. This affects Varnish Enterprise 6.0.x before 6.0.8r3, and Varnish Cache 5.x...Show more
Varnish Cache, with HTTP/2 enabled, allows request smuggling and VCL authorization bypass via a large Content-Length header for a POST request. This affects Varnish Enterprise 6.0.x before 6.0.8r3, and Varnish Cache 5.x and 6.x before 6.5.2, 6.6.x before 6.6.1, and 6.0 LTS before 6.0.8.Show less
1Sap
2Internet Communication Manager
Web Dispatcher
Jun 17, 2026
Jul 14, 2021
N/A· v4
4.3 MEDIUM· v3
4.0 MEDIUM· v2
SAP Web Dispatcher and Internet Communication Manager (ICM), versions - KRNL32NUC 7.21, 7.21EXT, 7.22, 7.22EXT, KRNL32UC 7.21, 7.21EXT, 7.22, 7.22EXT, KRNL64NUC 7.21, 7.21EXT, 7.22, 7.22EXT, 7.49, KRNL64UC 7.21, 7.21EXT,...Show more
SAP Web Dispatcher and Internet Communication Manager (ICM), versions - KRNL32NUC 7.21, 7.21EXT, 7.22, 7.22EXT, KRNL32UC 7.21, 7.21EXT, 7.22, 7.22EXT, KRNL64NUC 7.21, 7.21EXT, 7.22, 7.22EXT, 7.49, KRNL64UC 7.21, 7.21EXT, 7.22, 7.22EXT, 7.49, 7.53, 7.73, WEBDISP 7.53, 7.73, 7.77, 7.81, 7.82, 7.83, KERNEL 7.21, 7.22, 7.49, 7.53, 7.73, 7.77, 7.81, 7.82, 7.83, process invalid HTTP header. The incorrect handling of the invalid Transfer-Encoding header in a particular manner leads to a possibility of HTTP Request Smuggling attack. An attacker could exploit this vulnerability to bypass web application firewall protection, divert sensitive data such as customer requests, session credentials, etc.Show less
4Apache
DebianMcafee+1 more
22Agile Plm
Communications Cloud Native Core PolicyCommunications Cloud Native Core Service Communication Proxy+19 more
Jun 17, 2026
Jul 12, 2021
N/A· v4
5.3 MEDIUM· v3
5.0 MEDIUM· v2
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...Show more
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 proxy. Specifically: - Tomcat incorrectly ignored the transfer encoding header if the client declared it would only accept an HTTP/1.0 response; - Tomcat honoured the identify encoding; and - Tomcat did not ensure that, if present, the chunked encoding was the final encoding.Show less
1Hyper
1Hyper
Jun 17, 2026
Jul 7, 2021
N/A· v4
5.3 MEDIUM· v3
4.3 MEDIUM· v2
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...Show more
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 proxy that doesn't parse such `Content-Length` headers, but forwards them, can result in "request smuggling" or "desync attacks". The flaw exists in all prior versions of hyper prior to 0.14.10, if built with `rustc` v1.5.0 or newer. The vulnerability is patched in hyper version 0.14.10. Two workarounds exist: One may reject requests manually that contain a plus sign prefix in the `Content-Length` header or ensure any upstream proxy handles `Content-Length` headers with a plus sign prefix.Show less
2Apache
Debian
2Debian Linux
Traffic Server
Jun 17, 2026
Jun 29, 2021
N/A· v4
7.5 HIGH· v3
5.0 MEDIUM· v2
Invalid values in the Content-Length header sent to Apache Traffic Server allows an attacker to smuggle requests. This issue affects Apache Traffic Server 7.0.0 to 7.1.12, 8.0.0 to 8.1.1, 9.0.0 to 9.0.1.
2Apache
Debian
2Debian Linux
Traffic Server
Jun 17, 2026
Jun 29, 2021
N/A· v4
7.5 HIGH· v3
5.0 MEDIUM· v2
Incorrect handling of url fragment vulnerability of Apache Traffic Server allows an attacker to poison the cache. This issue affects Apache Traffic Server 7.0.0 to 7.1.12, 8.0.0 to 8.1.1, 9.0.0 to 9.0.1.
3Apache
FedoraprojectOracle
5Enterprise Manager Ops Center
FedoraHttp Server+2 more
Jun 17, 2026
Jun 10, 2021
N/A· v4
5.3 MEDIUM· v3
5.0 MEDIUM· v2
Apache HTTP Server versions 2.4.6 to 2.4.46 mod_proxy_wstunnel configured on an URL that is not necessarily Upgraded by the origin server was tunneling the whole connection regardless, thus allowing for subsequent reques...Show more
Apache HTTP Server versions 2.4.6 to 2.4.46 mod_proxy_wstunnel configured on an URL that is not necessarily Upgraded by the origin server was tunneling the whole connection regardless, thus allowing for subsequent requests on the same connection to pass through with no HTTP validation, authentication or authorization possibly configured.Show less
1Apache
1Dubbo
Jun 17, 2026
Jun 1, 2021
N/A· v4
9.8 CRITICAL· v3
6.8 MEDIUM· v2
Apache Dubbo prior to 2.7.9 support Tag routing which will enable a customer to route the request to the right server. These rules are used by the customers when making a request in order to find the right endpoint. When...Show more
Apache Dubbo prior to 2.7.9 support Tag routing which will enable a customer to route the request to the right server. These rules are used by the customers when making a request in order to find the right endpoint. When parsing these YAML rules, Dubbo customers may enable calling arbitrary constructors.Show less
1Pulsesecure
1Virtual Traffic Manager
Jun 17, 2026
May 14, 2021
N/A· v4
7.5 HIGH· v3
5.0 MEDIUM· v2
An HTTP Request Smuggling vulnerability in Pulse Secure Virtual Traffic Manager before 21.1 could allow an attacker to smuggle an HTTP request through an HTTP/2 Header. This vulnerability is resolved in 21.1, 20.3R1, 20....Show more
An HTTP Request Smuggling vulnerability in Pulse Secure Virtual Traffic Manager before 21.1 could allow an attacker to smuggle an HTTP request through an HTTP/2 Header. This vulnerability is resolved in 21.1, 20.3R1, 20.2R1, 20.1R2, 19.2R4, and 18.2R3.Show less