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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.

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CVEs (356)

CVE
VENDORS
PRODUCTS
UPDATED
PUBLISHED
CVSS
1Envoyproxy
1Envoy
Jun 17, 2026
Jul 25, 2023
N/A· v4
5.3 MEDIUM· v3
N/A· v2
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,...Show more
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, and 1.23.12, this can lead to the rejection of requests with mixed-case schemes such as `htTp` or `htTps`, or the bypassing of some requests such as `https` in unencrypted connections. With a fix in versions 1.27.0, 1.26.4, 1.25.9, 1.24.10, and 1.23.12, Envoy will now lowercase scheme values by default, and change the internal scheme checks that were case-sensitive to be case-insensitive. There are no known workarounds for this issue.Show less
1Aiohttp
1Aiohttp
Jun 17, 2026
Jul 19, 2023
N/A· v4
7.5 HIGH· v3
N/A· v2
aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. aiohttp v3.8.4 and earlier are bundled with llhttp v6.0.6. Vulnerable code is used by aiohttp for its HTTP request parser when available whi...Show more
aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. aiohttp v3.8.4 and earlier are bundled with llhttp v6.0.6. Vulnerable code is used by aiohttp for its HTTP request parser when available which is the default case when installing from a wheel. This vulnerability only affects users of aiohttp as an HTTP server (ie `aiohttp.Application`), you are not affected by this vulnerability if you are using aiohttp as an HTTP client library (ie `aiohttp.ClientSession`). Sending a crafted HTTP request will cause the server to misinterpret one of the HTTP header values leading to HTTP request smuggling. This issue has been addressed in version 3.8.5. Users are advised to upgrade. Users unable to upgrade can reinstall aiohttp using `AIOHTTP_NO_EXTENSIONS=1` as an environment variable to disable the llhttp HTTP request parser implementation. The pure Python implementation isn't vulnerable.Show less
1Sap
1Web Dispatcher
Jun 17, 2026
Jul 11, 2023
N/A· v4
9.4 CRITICAL· v3
N/A· v2
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...Show more
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, KERNEL 7.81, KERNEL 7.85, KERNEL 7.88, KERNEL 7.89, KERNEL 7.90, KRNL64NUC 7.49, KRNL64UC 7.49, KRNL64UC 7.53, HDB 2.00, XS_ADVANCED_RUNTIME 1.00, SAP_EXTENDED_APP_SERVICES 1, can 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 information on the server or make it temporarily unavailable. Show less
1Drogon
1Drogon
Jun 17, 2026
Jul 6, 2023
N/A· v4
6.1 MEDIUM· v3
N/A· v2
All versions of the package drogonframework/drogon are vulnerable to HTTP Response Splitting when untrusted user input is used to build header values in the addHeader and addCookie functions. An attacker can add the \r\n...Show more
All versions of the package drogonframework/drogon are vulnerable to HTTP Response Splitting when untrusted user input is used to build header values in the addHeader and addCookie functions. An attacker can add the \r\n (carriage return line feeds) characters to end the HTTP response headers and inject malicious content.Show less
1Emby
1Emby.releases
Jun 17, 2026
May 30, 2023
N/A· v4
9.1 CRITICAL· v3
N/A· v2
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...Show more
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 allow administrative access to an Emby Server system, depending on certain user account settings. By spoofing certain headers which are intended for interoperation with reverse proxy servers, it may be possible to affect the local/non-local network determination to allow logging in without password or to view a list of user accounts which may have no password configured. Impacted are all Emby Server system which are publicly accessible and where the administrator hasn't tightened the account login configuration for administrative users. This issue has been patched in Emby Server Beta version 4.8.31 and Emby Server version 4.7.12. Show less
1Lavalite
1Lavalite
Jun 17, 2026
May 12, 2023
N/A· v4
9.8 CRITICAL· v3
N/A· v2
LavaLite CMS v 9.0.0 was discovered to be vulnerable to web cache poisoning.
1Haproxy
1Haproxy
Jun 17, 2026
Apr 11, 2023
N/A· v4
7.3 HIGH· v3
N/A· v2
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 caus...Show more
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-service (DoS) condition.Show less
1Envoyproxy
1Envoy
Jun 17, 2026
Apr 4, 2023
N/A· v4
9.1 CRITICAL· v3
N/A· v2
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 re...Show more
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 can lead to characters that are illegal in header values to be sent to the upstream service. In the worst case, it can cause upstream service to interpret the original request as two pipelined requests, possibly bypassing the intent of Envoy’s security policy. Versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9 contain a patch. As a workaround, disable adding request headers based on the downstream request properties, such as downstream certificate properties.Show less
1Envoyproxy
1Envoy
Jun 17, 2026
Apr 4, 2023
N/A· v4
9.1 CRITICAL· v3
N/A· v2
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 i...Show more
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 that non compliant HTTP/1 service may allow malformed requests, potentially leading to a bypass of security policies. This issue is fixed in versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9.Show less
2Fedoraproject
Mediawiki
2Fedora
Mediawiki
Jun 17, 2026
Mar 31, 2023
N/A· v4
9.8 CRITICAL· v3
N/A· v2
An issue was discovered in MediaWiki before 1.35.10, 1.36.x through 1.38.x before 1.38.6, and 1.39.x before 1.39.3. An auto-block can occur for an untrusted X-Forwarded-For header.
3Apache
DebianUnbit
3Debian Linux
Http ServerUwsgi
Jun 17, 2026
Mar 7, 2023
N/A· v4
7.5 HIGH· v3
N/A· v2
HTTP Response Smuggling vulnerability in Apache HTTP Server via mod_proxy_uwsgi. This issue affects Apache HTTP Server: from 2.4.30 through 2.4.55. Special characters in the origin response header can truncate/split the...Show more
HTTP Response Smuggling vulnerability in Apache HTTP Server via mod_proxy_uwsgi. This issue affects Apache HTTP Server: from 2.4.30 through 2.4.55. Special characters in the origin response header can truncate/split the response forwarded to the client.Show less
1Apache
1Http Server
Jun 17, 2026
Mar 7, 2023
N/A· v4
9.8 CRITICAL· v3
N/A· v2
Some mod_proxy configurations on Apache HTTP Server versions 2.4.0 through 2.4.55 allow a HTTP Request Smuggling attack. Configurations are affected when mod_proxy is enabled along with some form of RewriteRule or P...Show more
Some mod_proxy configurations on Apache HTTP Server versions 2.4.0 through 2.4.55 allow a HTTP Request Smuggling attack. Configurations are affected when mod_proxy is enabled along with some form of RewriteRule or ProxyPassMatch in which a non-specific pattern matches some portion of the user-supplied request-target (URL) data and is then re-inserted into the proxied request-target using variable substitution. For example, something like: RewriteEngine on RewriteRule "^/here/(.*)" "http://example.com:8080/elsewhere?$1"; [P] ProxyPassReverse /here/ http://example.com:8080/ Request splitting/smuggling could result in bypass of access controls in the proxy server, proxying unintended URLs to existing origin servers, and cache poisoning. Users are recommended to update to at least version 2.4.56 of Apache HTTP Server.Show less
2Debian
Haproxy
2Debian Linux
Haproxy
Jun 17, 2026
Feb 14, 2023
N/A· v4
9.1 CRITICAL· v3
N/A· v2
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,...Show more
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 used to truncate the list of HTTP headers and thus make some headers disappear after being parsed and processed for HTTP/1.0 and HTTP/1.1. For HTTP/2 and HTTP/3, the impact is limited because the headers disappear before being parsed and processed, as if they had not been sent by the client. The fixed versions are 2.7.3, 2.6.9, 2.5.12, 2.4.22, 2.2.29, and 2.0.31.Show less
1Dell
3Powervault Me5012 Firmware
Powervault Me5024 FirmwarePowervault Me5084 Firmware
Jun 17, 2026
Jan 20, 2023
N/A· v4
8.8 HIGH· v3
N/A· v2
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 i...Show more
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 the website, typically leading to XSS and DoS. Show less
1Apache
1Http Server
Jun 17, 2026
Jan 17, 2023
N/A· v4
9.0 CRITICAL· v3
N/A· v2
Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling') vulnerability in mod_proxy_ajp of Apache HTTP Server allows an attacker to smuggle requests to the AJP server it forwards requests to. This issue a...Show more
Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling') vulnerability in mod_proxy_ajp of Apache HTTP Server allows an attacker to smuggle requests to the AJP server it forwards requests to. This issue affects Apache HTTP Server Apache HTTP Server 2.4 version 2.4.54 and prior versions.Show less
1Golang
1H2c
Jun 17, 2026
Jan 13, 2023
N/A· v4
7.5 HIGH· v3
N/A· v2
A request smuggling attack is possible when using MaxBytesHandler. When using MaxBytesHandler, the body of an HTTP request is not fully consumed. When the server attempts to read HTTP2 frames from the connection, it will...Show more
A request smuggling attack is possible when using MaxBytesHandler. When using MaxBytesHandler, the body of an HTTP request is not fully consumed. When the server attempts to read HTTP2 frames from the connection, it will instead be reading the body of the HTTP request, which could be attacker-manipulated to represent arbitrary HTTP2 requests.Show less
4Debian
LlhttpNodejs+1 more
4Debian Linux
LlhttpNode.js+1 more
Jun 17, 2026
Dec 5, 2022
N/A· v4
6.5 MEDIUM· v3
N/A· v2
The llhttp parser in the http module in Node v18.7.0 does not correctly handle header fields that are not terminated with CLRF. This may result in HTTP Request Smuggling.
1Solarwinds
1Security Event Manager
Jun 17, 2026
Nov 23, 2022
N/A· v4
6.1 MEDIUM· v3
N/A· v2
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.
2Fedoraproject
Varnish Cache Project
2Fedora
Varnish Cache
Jun 17, 2026
Nov 9, 2022
N/A· v4
7.5 HIGH· v3
N/A· v2
An issue was discovered in Varnish Cache 7.x before 7.1.2 and 7.2.x before 7.2.1. A request smuggling attack can be performed on Varnish Cache servers by requesting that certain headers are made hop-by-hop, preventing th...Show more
An issue was discovered in Varnish Cache 7.x before 7.1.2 and 7.2.x before 7.2.1. A request smuggling attack can be performed on Varnish Cache servers by requesting that certain headers are made hop-by-hop, preventing the Varnish Cache servers from forwarding critical headers to the backend.Show less
1Apache
1Tomcat
Jun 17, 2026
Nov 1, 2022
N/A· v4
7.5 HIGH· v3
N/A· v2
If Apache Tomcat 8.5.0 to 8.5.82, 9.0.0-M1 to 9.0.67, 10.0.0-M1 to 10.0.26 or 10.1.0-M1 to 10.1.0 was configured to ignore invalid HTTP headers via setting rejectIllegalHeader to false (the default for 8.5.x only), Tomca...Show more
If Apache Tomcat 8.5.0 to 8.5.82, 9.0.0-M1 to 9.0.67, 10.0.0-M1 to 10.0.26 or 10.1.0-M1 to 10.1.0 was configured to ignore invalid HTTP headers via setting rejectIllegalHeader to false (the default for 8.5.x only), Tomcat did not reject a request containing an invalid Content-Length header making a request smuggling attack possible if Tomcat was located behind a reverse proxy that also failed to reject the request with the invalid header.Show less