CWE-444
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Description
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.
Hierarchy (View 1000)
Parents
Children
none
Related attack patterns (CAPEC)
CAPEC-273 · CAPEC-33
CVEs mapped to this weakness (200)
page 3 of 10| CVE | Vendor / Product | Sev | Risk | CVSS | EPSS | KEV | Published | Description |
|---|---|---|---|---|---|---|---|---|
| CVE-2025-6999 | Med | 0.45 | — | 0.01 | Sep 15, 2025 | An HTTP Request Smuggling [CWE-444] vulnerability in the Authentication portal of WatchGuard Fireware OS allows a remote attacker to evade request parameter sanitation and perform a reflected self-Cross-Site Scripting (XSS) attack.This issue affects Fireware OS: from 12.0… | ||
| CVE-2024-56908 | Med | 0.44 | 6.8 | 0.01 | Feb 13, 2025 | In Perfex Crm < 3.2.1, an authenticated attacker can send a crafted HTTP POST request to the affected upload_sales_file endpoint. By providing malicious input in the rel_id parameter, combined with improper input validation, the attacker can bypass restrictions and upload… | ||
| CVE-2026-42585 | Med | 0.42 | 6.5 | 0.00 | May 13, 2026 | 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.Final and 4.1.133.Final. | ||
| CVE-2026-42580 | Med | 0.42 | 6.5 | 0.00 | May 13, 2026 | Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty's chunk size parser silently overflows int, enabling request smuggling attacks. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final. | ||
| CVE-2026-40560 | Hig | 0.42 | 7.5 | 0.00 | Apr 29, 2026 | 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 RFC 7230 3.3.3, Transfer-Encoding must… | ||
| CVE-2026-24880 | Hig | 0.42 | 7.5 | 0.00 | Apr 9, 2026 | 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, from 9.0.0.M1 through 9.0.115, from… | ||
| CVE-2025-65114 | Hig | 0.42 | 7.5 | 0.00 | Apr 2, 2026 | 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 10.1.2, which fix the issue. | ||
| CVE-2025-23167 | Med | 0.42 | 6.5 | 0.00 | May 19, 2025 | A flaw in Node.js 20's HTTP parser allows improper termination of HTTP/1 headers using `\r\n\rX` instead of the required `\r\n\r\n`. This inconsistency enables request smuggling, allowing attackers to bypass proxy-based access controls and submit unauthorized requests. The… | ||
| CVE-2025-31137 | Hig | 0.42 | 7.5 | 0.01 | Apr 1, 2025 | 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 vulnerability allows anyone to spoof the… | ||
| CVE-2024-6827 | Hig | 0.42 | 7.5 | 0.01 | Mar 20, 2025 | 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 smuggling. This vulnerability can lead to cache… | ||
| CVE-2024-27982 | Med | 0.42 | 6.5 | 0.01 | May 7, 2024 | The team has identified a critical vulnerability in the http server of the most recent version of Node, where malformed headers can lead to HTTP request smuggling. Specifically, if a space is placed before a content-length header, it is not interpreted correctly, enabling… | ||
| CVE-2024-1135 | Hig | 0.42 | 7.5 | 0.03 | Apr 16, 2024 | Gunicorn fails to properly validate Transfer-Encoding headers, leading to HTTP Request Smuggling (HRS) vulnerabilities. By crafting requests with conflicting Transfer-Encoding headers, attackers can bypass security restrictions and access restricted endpoints. This issue is due… | ||
| CVE-2017-2666 | — | Med | 0.42 | 6.5 | 0.03 | Jul 27, 2018 | It was discovered in Undertow that the code that parsed the HTTP request line permitted invalid characters. This could be exploited, in conjunction with a proxy that also permitted the invalid characters but with a different interpretation, to inject data into the HTTP response.… | |
| CVE-2025-12874 | Med | 0.41 | — | 0.00 | Dec 19, 2025 | Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in Quest Coexistence Manager for Notes (Free/Busy Connector modules) allows HTTP Request Smuggling via the Content-Length-Transfer-Encoding (CL.TE) attack vector. This could allow an… | ||
| CVE-2024-12397 | Hig | 0.41 | 7.4 | 0.01 | Dec 12, 2024 | A flaw was found in Quarkus-HTTP, which incorrectly parses cookies with certain value-delimiting characters in incoming requests. This issue could allow an attacker to construct a cookie value to exfiltrate HttpOnly cookie values or spoof arbitrary additional cookie values,… | ||
| CVE-2023-4639 | Hig | 0.41 | 7.4 | 0.01 | Nov 17, 2024 | A flaw was found in Undertow, which incorrectly parses cookies with certain value-delimiting characters in incoming requests. This issue could allow an attacker to construct a cookie value to exfiltrate HttpOnly cookie values or spoof arbitrary additional cookie values, leading… | ||
| CVE-2018-7068 | Med | 0.40 | 6.1 | 0.01 | Aug 6, 2018 | HPE has identified a remote HOST header attack vulnerability in HPE CentralView Fraud Risk Management earlier than version CV 6.1. This issue is resolved in HF16 for HPE CV 6.1 or subsequent version. | ||
| CVE-2017-7559 | Med | 0.40 | 6.1 | 0.02 | Jan 10, 2018 | In Undertow 2.x before 2.0.0.Alpha2, 1.4.x before 1.4.17.Final, and 1.3.x before 1.3.31.Final, it was found that the fix for CVE-2017-2666 was incomplete and invalid characters are still allowed in the query string and path parameters. This could be exploited, in conjunction… | ||
| CVE-2026-52845 | hig | 0.38 | — | 0.00 | Jun 16, 2026 | ### Summary `forward_auth copy_headers` deletes the exact client-supplied identity header before copying the trusted value from the auth gateway. But when the request later goes through `php_fastcgi`, Caddy normalizes HTTP headers into CGI variables by replacing `-` with `_`. … | ||
| CVE-2026-42581 | Med | 0.38 | 5.8 | 0.01 | May 13, 2026 | Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpObjectDecoder strips a conflicting Content-Length header when a request carries both Transfer-Encoding: chunked and Content-Length, but only for HTTP/1.1 messages.… |
- risk 0.45cvss —epss 0.01
An HTTP Request Smuggling [CWE-444] vulnerability in the Authentication portal of WatchGuard Fireware OS allows a remote attacker to evade request parameter sanitation and perform a reflected self-Cross-Site Scripting (XSS) attack.This issue affects Fireware OS: from 12.0…
- risk 0.44cvss 6.8epss 0.01
In Perfex Crm < 3.2.1, an authenticated attacker can send a crafted HTTP POST request to the affected upload_sales_file endpoint. By providing malicious input in the rel_id parameter, combined with improper input validation, the attacker can bypass restrictions and upload…
- risk 0.42cvss 6.5epss 0.00
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.Final and 4.1.133.Final.
- risk 0.42cvss 6.5epss 0.00
Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Netty's chunk size parser silently overflows int, enabling request smuggling attacks. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.
- risk 0.42cvss 7.5epss 0.00
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 RFC 7230 3.3.3, Transfer-Encoding must…
- risk 0.42cvss 7.5epss 0.00
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, from 9.0.0.M1 through 9.0.115, from…
- risk 0.42cvss 7.5epss 0.00
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 10.1.2, which fix the issue.
- risk 0.42cvss 6.5epss 0.00
A flaw in Node.js 20's HTTP parser allows improper termination of HTTP/1 headers using `\r\n\rX` instead of the required `\r\n\r\n`. This inconsistency enables request smuggling, allowing attackers to bypass proxy-based access controls and submit unauthorized requests. The…
- risk 0.42cvss 7.5epss 0.01
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 vulnerability allows anyone to spoof the…
- risk 0.42cvss 7.5epss 0.01
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 smuggling. This vulnerability can lead to cache…
- risk 0.42cvss 6.5epss 0.01
The team has identified a critical vulnerability in the http server of the most recent version of Node, where malformed headers can lead to HTTP request smuggling. Specifically, if a space is placed before a content-length header, it is not interpreted correctly, enabling…
- risk 0.42cvss 7.5epss 0.03
Gunicorn fails to properly validate Transfer-Encoding headers, leading to HTTP Request Smuggling (HRS) vulnerabilities. By crafting requests with conflicting Transfer-Encoding headers, attackers can bypass security restrictions and access restricted endpoints. This issue is due…
- risk 0.42cvss 6.5epss 0.03
It was discovered in Undertow that the code that parsed the HTTP request line permitted invalid characters. This could be exploited, in conjunction with a proxy that also permitted the invalid characters but with a different interpretation, to inject data into the HTTP response.…
- risk 0.41cvss —epss 0.00
Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in Quest Coexistence Manager for Notes (Free/Busy Connector modules) allows HTTP Request Smuggling via the Content-Length-Transfer-Encoding (CL.TE) attack vector. This could allow an…
- risk 0.41cvss 7.4epss 0.01
A flaw was found in Quarkus-HTTP, which incorrectly parses cookies with certain value-delimiting characters in incoming requests. This issue could allow an attacker to construct a cookie value to exfiltrate HttpOnly cookie values or spoof arbitrary additional cookie values,…
- risk 0.41cvss 7.4epss 0.01
A flaw was found in Undertow, which incorrectly parses cookies with certain value-delimiting characters in incoming requests. This issue could allow an attacker to construct a cookie value to exfiltrate HttpOnly cookie values or spoof arbitrary additional cookie values, leading…
- risk 0.40cvss 6.1epss 0.01
HPE has identified a remote HOST header attack vulnerability in HPE CentralView Fraud Risk Management earlier than version CV 6.1. This issue is resolved in HF16 for HPE CV 6.1 or subsequent version.
- risk 0.40cvss 6.1epss 0.02
In Undertow 2.x before 2.0.0.Alpha2, 1.4.x before 1.4.17.Final, and 1.3.x before 1.3.31.Final, it was found that the fix for CVE-2017-2666 was incomplete and invalid characters are still allowed in the query string and path parameters. This could be exploited, in conjunction…
- risk 0.38cvss —epss 0.00
### Summary `forward_auth copy_headers` deletes the exact client-supplied identity header before copying the trusted value from the auth gateway. But when the request later goes through `php_fastcgi`, Caddy normalizes HTTP headers into CGI variables by replacing `-` with `_`. …
- risk 0.38cvss 5.8epss 0.01
Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpObjectDecoder strips a conflicting Content-Length header when a request carries both Transfer-Encoding: chunked and Content-Length, but only for HTTP/1.1 messages.…