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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
2Fedoraproject
Ruby Lang
3Fedora
RubyWebrick
Jun 17, 2026
Oct 6, 2020
N/A· v4
7.5 HIGH· v3
5.0 MEDIUM· v2
An issue was discovered in Ruby through 2.5.8, 2.6.x through 2.6.6, and 2.7.x through 2.7.1. WEBrick, a simple HTTP server bundled with Ruby, had not checked the transfer-encoding header value rigorously. An attacker may...Show more
An issue was discovered in Ruby through 2.5.8, 2.6.x through 2.6.6, and 2.7.x through 2.7.1. WEBrick, a simple HTTP server bundled with Ruby, had not checked the transfer-encoding header value rigorously. An attacker may potentially exploit this issue to bypass a reverse proxy (which also has a poor header check), which may lead to an HTTP Request Smuggling attack.Show less
1Redhat
3Jboss Enterprise Application Platform
Single Sign OnUndertow
Jun 17, 2026
Sep 23, 2020
N/A· v4
4.8 MEDIUM· v3
5.8 MEDIUM· v2
A flaw was discovered in all versions of Undertow before Undertow 2.2.0.Final, where HTTP request smuggling related to CVE-2017-2666 is possible against HTTP/1.x and HTTP/2 due to permitting invalid characters in an HTTP...Show more
A flaw was discovered in all versions of Undertow before Undertow 2.2.0.Final, where HTTP request smuggling related to CVE-2017-2666 is possible against HTTP/1.x and HTTP/2 due to permitting invalid characters in an HTTP request. This flaw allows an attacker to poison a web-cache, perform an XSS attack, or obtain sensitive information from request other than their own.Show less
3Fedoraproject
NodejsOpensuse
3Fedora
LeapNode.js
Jun 17, 2026
Sep 18, 2020
N/A· v4
7.4 HIGH· v3
5.8 MEDIUM· v2
Node.js < 12.18.4 and < 14.11 can be exploited to perform HTTP desync attacks and deliver malicious payloads to unsuspecting users. The payloads can be crafted by an attacker to hijack user sessions, poison cookies, perf...Show more
Node.js < 12.18.4 and < 14.11 can be exploited to perform HTTP desync attacks and deliver malicious payloads to unsuspecting users. The payloads can be crafted by an attacker to hijack user sessions, poison cookies, perform clickjacking, and a multitude of other attacks depending on the architecture of the underlying system. The attack was possible due to a bug in processing of carrier-return symbols in the HTTP header names.Show less
5Canonical
DebianFedoraproject+2 more
5Debian Linux
FedoraLeap+2 more
Jun 17, 2026
Sep 2, 2020
N/A· v4
6.5 MEDIUM· v3
3.5 LOW· v2
An issue was discovered in Squid before 4.13 and 5.x before 5.0.4. Due to incorrect data validation, HTTP Request Smuggling attacks may succeed against HTTP and HTTPS traffic. This leads to cache poisoning. This allows a...Show more
An issue was discovered in Squid before 4.13 and 5.x before 5.0.4. Due to incorrect data validation, HTTP Request Smuggling attacks may succeed against HTTP and HTTPS traffic. This leads to cache poisoning. This allows any client, including browser scripts, to bypass local security and poison the proxy cache and any downstream caches with content from an arbitrary source. When configured for relaxed header parsing (the default), Squid relays headers containing whitespace characters to upstream servers. When this occurs as a prefix to a Content-Length header, the frame length specified will be ignored by Squid (allowing for a conflicting length to be used from another Content-Length header) but relayed upstream.Show less
7Apache
CanonicalDebian+4 more
25Communications Element Manager
Communications Session Report ManagerCommunications Session Route Manager+22 more
Jun 17, 2026
Aug 7, 2020
N/A· v4
7.5 HIGH· v3
5.0 MEDIUM· v2
Apache HTTP Server versions 2.4.20 to 2.4.43. A specially crafted value for the 'Cache-Digest' header in a HTTP/2 request would result in a crash when the server actually tries to HTTP/2 PUSH a resource afterwards. Confi...Show more
Apache HTTP Server versions 2.4.20 to 2.4.43. A specially crafted value for the 'Cache-Digest' header in a HTTP/2 request would result in a crash when the server actually tries to HTTP/2 PUSH a resource afterwards. Configuring the HTTP/2 feature via "H2Push off" will mitigate this vulnerability for unpatched servers.Show less
7Apache
CanonicalDebian+4 more
13Clustered Data Ontap
Communications Element ManagerCommunications Session Report Manager+10 more
Jun 17, 2026
Aug 7, 2020
N/A· v4
7.5 HIGH· v3
4.3 MEDIUM· v2
Apache HTTP Server versions 2.4.20 to 2.4.43 When trace/debug was enabled for the HTTP/2 module and on certain traffic edge patterns, logging statements were made on the wrong connection, causing concurrent use of memory...Show more
Apache HTTP Server versions 2.4.20 to 2.4.43 When trace/debug was enabled for the HTTP/2 module and on certain traffic edge patterns, logging statements were made on the wrong connection, causing concurrent use of memory pools. Configuring the LogLevel of mod_http2 above "info" will mitigate this vulnerability for unpatched servers.Show less
1Silverstripe
1Silverstripe
Jun 17, 2026
Jul 15, 2020
N/A· v4
5.9 MEDIUM· v3
4.3 MEDIUM· v2
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-Me...Show more
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 headers, responses with malicious HTTP headers can return unexpected responses to other consumers of this cached response. Most other headers associated with web cache poisoning are already disabled through request hostname forgery whitelists.Show less
2Fedoraproject
Squid Cache
2Fedora
Squid
Jun 17, 2026
Jun 30, 2020
N/A· v4
8.8 HIGH· v3
6.5 MEDIUM· v2
An issue was discovered in http/ContentLengthInterpreter.cc in Squid before 4.12 and 5.x before 5.0.3. A Request Smuggling and Poisoning attack can succeed against the HTTP cache. The client sends an HTTP request with a...Show more
An issue was discovered in http/ContentLengthInterpreter.cc in Squid before 4.12 and 5.x before 5.0.3. A Request Smuggling and Poisoning attack can succeed against the HTTP cache. The client sends an HTTP request with a Content-Length header containing "+\ "-" or an uncommon shell whitespace character prefix to the length field-value.Show less
1Mattermost
1Mattermost Server
Jun 17, 2026
Jun 19, 2020
N/A· v4
5.3 MEDIUM· v3
5.0 MEDIUM· v2
An issue was discovered in Mattermost Server before 5.12.0. Use of a Proxy HTTP header, rather than the source address in an IP packet header, for obtaining IP address information was mishandled.
1Apsis
1Pound
Nov 21, 2024
Jun 15, 2020
N/A· v4
9.1 CRITICAL· v3
6.4 MEDIUM· v2
Pound before 2.8 allows HTTP request smuggling, a related issue to CVE-2016-10711.
1Goliath Project
1Goliath
Jun 17, 2026
Jun 10, 2020
N/A· v4
7.5 HIGH· v3
5.0 MEDIUM· v2
goliath through 1.0.6 allows request smuggling attacks where goliath is used as a backend and a frontend proxy also being vulnerable. It is possible to conduct HTTP request smuggling attacks by sending the Content-Length...Show more
goliath through 1.0.6 allows request smuggling attacks where goliath is used as a backend and a frontend proxy also being vulnerable. It is possible to conduct HTTP request smuggling attacks by sending the Content-Length header twice. Furthermore, invalid Transfer Encoding headers were found to be parsed as valid which could be leveraged for TE:CL smuggling attacks.Show less
1Ohler
1Agoo
Jun 17, 2026
Jun 10, 2020
N/A· v4
7.5 HIGH· v3
5.0 MEDIUM· v2
agoo prior to 2.14.0 allows request smuggling attacks where agoo is used as a backend and a frontend proxy also being vulnerable. HTTP pipelining issues and request smuggling attacks might be possible due to incorrect Co...Show more
agoo prior to 2.14.0 allows request smuggling attacks where agoo is used as a backend and a frontend proxy also being vulnerable. HTTP pipelining issues and request smuggling attacks might be possible due to incorrect Content-Length and Transfer encoding header parsing. It is possible to conduct HTTP request smuggling attacks where `agoo` is used as part of a chain of backend servers due to insufficient `Content-Length` and `Transfer Encoding` parsing.Show less
1Celluloid
1Reel
Jun 17, 2026
Jun 1, 2020
N/A· v4
7.5 HIGH· v3
5.0 MEDIUM· v2
reel through 0.6.1 allows Request Smuggling attacks due to incorrect Content-Length and Transfer encoding header parsing. It is possible to conduct HTTP request smuggling attacks by sending the Content-Length header twic...Show more
reel through 0.6.1 allows Request Smuggling attacks due to incorrect Content-Length and Transfer encoding header parsing. It is possible to conduct HTTP request smuggling attacks by sending the Content-Length header twice. Furthermore, invalid Transfer Encoding headers were found to be parsed as valid which could be leveraged for TE:CL smuggling attacks. Note: This project is deprecated, and is not maintained any more.Show less
2Netapp
Redhat
8Active Iq Unified Manager
FuseJboss Enterprise Application Platform+5 more
Jun 17, 2026
May 26, 2020
N/A· v4
6.5 MEDIUM· v3
6.4 MEDIUM· v2
A flaw was found in Undertow in versions before 2.1.1.Final, regarding the processing of invalid HTTP requests with large chunk sizes. This flaw allows an attacker to take advantage of HTTP request smuggling.
1Meinheld
1Meinheld
Jun 17, 2026
May 22, 2020
N/A· v4
6.1 MEDIUM· v3
4.3 MEDIUM· v2
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.
4Debian
FedoraprojectOpensuse+1 more
4Debian Linux
FedoraLeap+1 more
Jun 17, 2026
May 22, 2020
N/A· v4
7.5 HIGH· v3
5.0 MEDIUM· v2
In Puma (RubyGem) before 4.3.5 and 3.12.6, a client could smuggle a request through a proxy, causing the proxy to send a response back to another unknown client. If the proxy uses persistent connections and the client ad...Show more
In Puma (RubyGem) before 4.3.5 and 3.12.6, a client could smuggle a request through a proxy, causing the proxy to send a response back to another unknown client. 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 is a similar but different vulnerability from CVE-2020-11076. The problem has been fixed in Puma 3.12.6 and Puma 4.3.5.Show less
3Debian
FedoraprojectPuma
3Debian Linux
FedoraPuma
Jun 17, 2026
May 22, 2020
N/A· v4
7.5 HIGH· v3
5.0 MEDIUM· v2
In Puma (RubyGem) before 4.3.4 and 3.12.5, an attacker could smuggle an HTTP response, by using an invalid transfer-encoding header. The problem has been fixed in Puma 3.12.5 and Puma 4.3.4.
1Hive
1Netius
Jun 17, 2026
May 21, 2020
N/A· v4
6.1 MEDIUM· v3
4.3 MEDIUM· v2
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:...Show more
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.Show less
1Gitlab
1Gitlab
Jun 17, 2026
Apr 22, 2020
N/A· v4
7.5 HIGH· v3
5.0 MEDIUM· v2
An issue was discovered in GitLab 10.7.0 and later through 12.9.2. A Workhorse bypass could lead to job artifact uploads and file disclosure (Exposure of Sensitive Information) via request smuggling.
1Gitlab
1Gitlab
Jun 17, 2026
Apr 22, 2020
N/A· v4
7.5 HIGH· v3
5.0 MEDIUM· v2
An issue was discovered in GitLab Community Edition (CE) and Enterprise Edition (EE) before 12.7.9, 12.8.x before 12.8.9, and 12.9.x before 12.9.3. A Workhorse bypass could lead to NuGet package and file disclosure (Expo...Show more
An issue was discovered in GitLab Community Edition (CE) and Enterprise Edition (EE) before 12.7.9, 12.8.x before 12.8.9, and 12.9.x before 12.9.3. A Workhorse bypass could lead to NuGet package and file disclosure (Exposure of Sensitive Information) via request smuggling.Show less