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 9 of 10
- CVE-2026-75922MEDIUMCVSS 5.3EG 5.32026-08-23
Reverse::Proxy versions before 0.04 for Perl allow HTTP request smuggling via a percent-decoded PATH_INFO written unencoded to the upstream request line. PSGI hands PATH_INFO to an application percent-decoded, so a %XX sequence in the cli…
- CVE-2026-14180MEDIUMCVSS 5.3EG 5.32026-08-11
A flaw was found in the ChunkReader component of the Undertow HTTP server, which is used by WildFly and JBoss EAP to handle chunked transfer encoding. The issue occurs because the parser uses a single internal variable to store both the re…
- CVE-2026-71554MEDIUMCVSS 5.3EG 5.32026-08-06
h2 is a pure-Python implementation of a HTTP/2 protocol stack. Versions up to and including 4.4.0 accept request header blocks containing more than one Host header, and forward every Host header to the consuming application. Where the cons…
- CVE-2026-64785MEDIUMCVSS 5.3EG 5.32026-07-23
SwiftNIO HTTP/2 was missing validation on inbound HEADERS frames that let CR, LF, NUL, SP and other control characters reach an HTTP/1.1 backend through NIOHTTP2's HTTP/2-to-HTTP/1 codec, enabling HTTP request smuggling or response splitti…
- CVE-2026-59900MEDIUMCVSS 5.3EG 5.32026-07-22
Netty is an asynchronous, event-driven network application framework. Prior to versions 4.1.136.Final and 4.2.16.Final, Netty's HTTP/2-to-HTTP/1.x translation layer (`Http2StreamFrameToHttpObjectCodec` and `InboundHttp2ToHttpAdapter`) fail…
- CVE-2026-12606MEDIUMCVSS 5.3EG 5.32026-07-14
Eclipse Grizzly in versions before 5.0.2, cannot properly parse the trailer section in malformed trailer header's line, which can be leveraged to perform HTTP request smuggling. Grizzly 5.0.1 supports system properties that enable the beha…
- CVE-2026-50020MEDIUMCVSS 5.3EG 5.32026-06-12
Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, before reading the first request-line, `HttpObjectDecoder` skips every byte for which `Character.is…
- CVE-2026-28898MEDIUMCVSS 5.3EG 5.32026-06-12
swift-nio-http2's HTTP/2-to-HTTP/1.1 codec did not validate pseudo-header values for control characters before placing them into the translated HTTP/1.1 message. swift-nio-http2 1.44.1 adds validation of all pseudo-header values (:path, :a…
- CVE-2026-41853MEDIUMCVSS 5.3EG 5.32026-06-09
Spring MVC and WebFlux applications are vulnerable to Multipart request smuggling attacks. Affected versions: Spring Framework 7.0.0 through 7.0.7; 6.2.0 through 6.2.18; 6.1.0 through 6.1.27; 5.3.0 through 5.3.48.
- CVE-2026-44546MEDIUMCVSS 5.3EG 5.32026-06-03
daphne before 4.2.2 reconstructs a raw HTTP request from Twisted's parsed headers and feeds it to autobahn for WebSocket handshake processing. Twisted does not treat \x0b, \x0c, \x1c, \x1d, \x1e, or \x85 as header line separators, but auto…
- CVE-2026-47676MEDIUMCVSS 5.3EG 5.32026-05-28
Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.21, app.mount() strips the mount prefix from the incoming request path using the raw URL pathname, while route matching is performed agains…
- CVE-2026-41417MEDIUMCVSS 5.3EG 5.32026-05-06
Netty allows request-line validation to be bypassed when a `DefaultHttpRequest` or `DefaultFullHttpRequest` is created first and its URI is later changed via `setUri()`. The constructors reject CRLF and whitespace characters that would bre…
- CVE-2026-40561MEDIUMCVSS 5.3EG 5.32026-05-03
Starlet versions through 0.31 for Perl allows HTTP Request Smuggling via Improper Header Precedence. Starlet incorrectly prioritizes "Content-Length" over "Transfer-Encoding: chunked" when both headers are present in an HTTP request. Per …
- CVE-2026-2708MEDIUMCVSS 5.3EG 5.32026-04-23
A request smuggling vulnerability exists in libsoup's HTTP/1 header parsing logic. The soup_message_headers_append_common() function in libsoup/soup-message-headers.c unconditionally appends each header value without validating for duplica…
- CVE-2026-34525MEDIUMCVSS 5.3EG 5.32026-04-01
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, multiple Host headers were allowed in aiohttp. This issue has been patched in version 3.13.4.
- CVE-2026-2862MEDIUMCVSS 5.3EG 5.32026-04-01
IBM Verify Identity Access Container 11.0 through 11.0.2 and IBM Security Verify Access Container 10.0 through 10.0.9.1 and IBM Verify Identity Access 11.0 through 11.0.2 and IBM Security Verify Access 10.0 through 10.0.9.1 IBM Security Ve…
- CVE-2026-1491MEDIUMCVSS 5.3EG 5.32026-04-01
IBM Verify Identity Access Container 11.0 through 11.0.2 and IBM Security Verify Access Container 10.0 through 10.0.9.1 and IBM Verify Identity Access 11.0 through 11.0.2 and IBM Security Verify Access 10.0 through 10.0.9.1 IBM Security Ve…
- CVE-2026-1760MEDIUMCVSS 5.3EG 5.32026-02-02
A flaw was found in SoupServer. This HTTP request smuggling vulnerability occurs because SoupServer improperly handles requests that combine Transfer-Encoding: chunked and Connection: keep-alive headers. A remote, unauthenticated client ca…
- CVE-2026-1002MEDIUMCVSS 5.3EG 5.32026-01-15
The Vert.x Web static handler component cache can be manipulated to deny the access to static files served by the handler using specifically crafted request URI. The issue comes from an improper implementation of the C. rule of section 5…
- CVE-2025-69225MEDIUMCVSS 5.3EG 5.32026-01-06
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Versions 3.13.2 and below contain parser logic which allows non-ASCII decimals to be present in the Range header. There is no known impact, but there is the po…
- CVE-2025-29904MEDIUMCVSS 5.3EG 5.32025-03-12
In JetBrains Ktor before 3.1.1 an HTTP Request Smuggling was possible
- CVE-2024-53008MEDIUMCVSS 5.3EG 5.32024-11-28
Inconsistent interpretation of HTTP requests ('HTTP Request/Response Smuggling') issue exists in HAProxy. If this vulnerability is exploited, a remote attacker may access a path that is restricted by ACL (Access Control List) set on the p…
- CVE-2024-21281MEDIUMCVSS 5.3EG 5.32024-10-15
Vulnerability in the Oracle Banking Liquidity Management product of Oracle Financial Services Applications (component: Infrastructure). The supported version that is affected is 14.7.0.6.0. Difficult to exploit vulnerability allows high …
- CVE-2024-9622MEDIUMCVSS 5.3EG 5.32024-10-08
A vulnerability was found in the resteasy-netty4 library arising from improper handling of HTTP requests using smuggling techniques. When an HTTP smuggling request with an ASCII control character is sent, it causes the Netty HttpObjectDeco…
- CVE-2024-35538MEDIUMCVSS 5.3EG 5.32024-08-19
Typecho v1.3.0 was discovered to contain a Client IP Spoofing vulnerability, which allows attackers to falsify their IP addresses by specifying an arbitrary IP as value of X-Forwarded-For or Client-Ip headers while performing HTTP requests.
- CVE-2024-20915MEDIUMCVSS 5.3EG 5.32024-02-17
Vulnerability in the Oracle Application Object Library product of Oracle E-Business Suite (component: Login - SSO). Supported versions that are affected are 12.2.3-12.2.13. Easily exploitable vulnerability allows unauthenticated attacker …
- CVE-2023-46846MEDIUMCVSS 5.3EG 5.32023-11-03
SQUID is vulnerable to HTTP request smuggling, caused by chunked decoder lenience, allows a remote attacker to perform Request/Response smuggling past firewall and frontend security systems.
- CVE-2023-46137MEDIUMCVSS 5.3EG 5.32023-10-25
Twisted is an event-based framework for internet applications. Prior to version 23.10.0rc1, when sending multiple HTTP requests in one TCP packet, twisted.web will process the requests asynchronously without guaranteeing the response order…
- CVE-2023-34037MEDIUMCVSS 5.3EG 5.32023-08-04
VMware Horizon Server contains a HTTP request smuggling vulnerability. A malicious actor with network access may be able to perform HTTP smuggle requests.
- CVE-2023-37276MEDIUMCVSS 5.3EG 5.32023-07-19
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 c…
- CVE-2021-21966MEDIUMCVSS 5.3EG 5.32022-02-16
An information disclosure vulnerability exists in the HTTP Server /ping.html functionality of Texas Instruments CC3200 SimpleLink Solution NWP 2.9.0.0. A specially-crafted HTTP request can lead to an uninitialized read. An attacker can sen…
- CVE-2021-31923MEDIUMCVSS 5.3EG 5.32021-09-24
Ping Identity PingAccess before 5.3.3 allows HTTP request smuggling via header manipulation.
- CVE-2021-25762MEDIUMCVSS 5.3EG 5.32021-02-03
In JetBrains Ktor before 1.4.3, HTTP Request Smuggling was possible.
- CVE-2019-20866MEDIUMCVSS 5.3EG 5.32020-06-19
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.
- CVE-2020-5401MEDIUMCVSS 5.3EG 5.32020-02-27
Cloud Foundry Routing Release, versions prior to 0.197.0, contains GoRouter, which allows malicious clients to send invalid headers, causing caching layers to reject subsequent legitimate clients trying to access the app.
- CVE-2019-20372MEDIUMCVSS 5.3EG 5.32020-01-09
NGINX before 1.17.7, with certain error_page configurations, allows HTTP request smuggling, as demonstrated by the ability of an attacker to read unauthorized web pages in environments where NGINX is being fronted by a load balancer.
- CVE-2019-18678MEDIUMCVSS 5.3EG 5.32019-11-26
An issue was discovered in Squid 3.x and 4.x through 4.8. It allows attackers to smuggle HTTP requests through frontend software to a Squid instance that splits the HTTP Request pipeline differently. The resulting Response messages corrupt…
- CVE-2023-46121MEDIUMCVSS 3.7EG 5.02023-11-15
yt-dlp is a youtube-dl fork with additional features and fixes. The Generic Extractor in yt-dlp is vulnerable to an attacker setting an arbitrary proxy for a request to an arbitrary url, allowing the attacker to MITM the request made from …
- CVE-2026-6338MEDIUMCVSS 4.9EG 4.92026-06-11
A HTTP request smuggling and desynchronization vulnerability affects Kong Gateway Enterprise 3.4, 3.10, 3.11, 3.12, 3.13, and 3.14 series. The vulnerability is caused by a parsing flaw in Kong’s HTTP request processing pipeline when hand…
- CVE-2025-1386MEDIUMCVSS 4.9EG 4.92025-04-11
When using the ch-go library, under a specific condition when the query includes a large, uncompressed malicious external data, it is possible for an attacker in control of such data to smuggle another query packet into the connection stre…
- CVE-2026-11722MEDIUMCVSS 4.8EG 4.82026-09-18
IBM WebSphere Application Server 8.5 and 9.0, and IBM WebSphere Application Server - Liberty 17.0.0.3 through 26.0.0.8 are affected by an HTTP request smuggling vulnerability.
- CVE-2026-11548MEDIUMCVSS 4.8EG 4.82026-09-18
IBM WebSphere Application Server 8.5 and 9.0, and and IBM WebSphere Application Server - Liberty 17.0.0.3 through 26.0.0.8 are affected by an HTTP request smuggling vulnerability.
- CVE-2026-10841MEDIUMCVSS 4.8EG 4.82026-09-18
IBM WebSphere Application Server 8.5 and 9.0, and IBM WebSphere Application Server - Liberty 17.0.0.3 through 26.0.0.8 are vulnerable to HTTP request smuggling.
- CVE-2026-6324MEDIUMCVSS 4.8EG 4.82026-05-29
A flaw was found in libsoup. A remote attacker could exploit an unsigned to signed conversion error in the `soup_body_input_stream_read_chunked()` function by sending a malicious HTTP request. This vulnerability occurs when libsoup operate…
- CVE-2026-40175MEDIUMCVSS 4.8EG 4.82026-04-10
Axios is a promise based HTTP client for the browser and Node.js. Versions prior to 1.15.0 and 0.3.1 are vulnerable to a specific gadget-style attack chain in which prototype pollution in a third-party dependency may be leveraged to inject…
- CVE-2025-66373MEDIUMCVSS 4.8EG 4.82025-12-04
Akamai Ghost on Akamai CDN edge servers before 2025-11-17 has a chunked request body processing error that can result in HTTP request smuggling. When Akamai Ghost receives an invalid chunked body that includes a chunk size different from t…
- CVE-2021-20220MEDIUMCVSS 4.8EG 4.82021-02-23
A flaw was found in Undertow. A regression in the fix for CVE-2020-10687 was found. 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 …
- CVE-2021-21299MEDIUMCVSS 4.8EG 4.82021-02-11
hyper is an open-source HTTP library for Rust (crates.io). In hyper from version 0.12.0 and before versions 0.13.10 and 0.14.3 there is a vulnerability that can enable a request smuggling attack. The HTTP server code had a flaw that incorr…
- CVE-2020-10687MEDIUMCVSS 4.8EG 4.82020-09-23
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…
- CVE-2020-1935MEDIUMCVSS 4.8EG 4.82020-02-24
In Apache Tomcat 9.0.0.M1 to 9.0.30, 8.5.0 to 8.5.50 and 7.0.0 to 7.0.99 the HTTP header parsing code used an approach to end-of-line parsing that allowed some invalid HTTP headers to be parsed as valid. This led to a possibility of HTTP R…
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