| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| Microsoft IIS 5.0 and 6.0 allows remote attackers to poison the web cache, bypass web application firewall protection, and conduct XSS attacks via an HTTP request with both a "Transfer-Encoding: chunked" header and a Content-Length header, which causes IIS to incorrectly handle and forward the body of the request in a way that causes the receiving server to process it as a separate HTTP request, aka "HTTP Request Smuggling." |
| The Apache HTTP server before 1.3.34, and 2.0.x before 2.0.55, when acting as an HTTP proxy, allows remote attackers to poison the web cache, bypass web application firewall protection, and conduct XSS attacks via an HTTP request with both a "Transfer-Encoding: chunked" header and a Content-Length header, which causes Apache to incorrectly handle and forward the body of the request in a way that causes the receiving server to process it as a separate HTTP request, aka "HTTP Request Smuggling." |
| H3 is a minimal H(TTP) framework built for high performance and portability. Prior to 1.15.5, there is a critical HTTP Request Smuggling vulnerability. readRawBody is doing a strict case-sensitive check for the Transfer-Encoding header. It explicitly looks for "chunked", but per the RFC, this header should be case-insensitive. This vulnerability is fixed in 1.15.5. |
| 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 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109.
Other, unsupported versions may also be affected.
Users are recommended to upgrade to version 11.0.20, 10.1.52 or 9.0.116, which fix the issue. |
| Connection desynchronization between an HTTP proxy and the model backend. The fixes were rolled out for all proxies in front of impacted models by 2025-09-28. Users do not need to take any action. |
| A flaw in libsoup’s HTTP header handling allows multiple Host: headers in a request and returns the last occurrence for server-side processing. Common front proxies often honor the first Host: header, so this mismatch can cause vhost confusion where a proxy routes a request to one backend but the backend interprets it as destined for another host. This discrepancy enables request-smuggling style attacks, cache poisoning, or bypassing host-based access controls when an attacker supplies duplicate Host headers. |
| Improper Inconsistent Interpretation of
HTTP Requests ('HTTP Request Smuggling') in Delinea Inc. Cloud Suite and
Privileged Access Service.
If you're not using the latest Server Suite agents, this fix requires that you upgrade to Server Suite 2023.1 (agent 6.0.1) or later. * If you cannot upgrade to Release 2023.1 (agent version 6.0.1) or later, you can choose one of the following versions:
* Server Suite release 2023.0.5 (agent version 6.0.0-158)
* Server Suite release 2022.1.10 (agent version 5.9.1-337) |
| 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 issue was resolved by upgrading `llhttp` to version 9, which enforces correct header termination.
Impact:
* This vulnerability affects only Node.js 20.x users prior to the `llhttp` v9 upgrade. |
| 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 to Gunicorn's handling of Transfer-Encoding headers, where it incorrectly processes requests with multiple, conflicting Transfer-Encoding headers, treating them as chunked regardless of the final encoding specified. This vulnerability allows for a range of attacks including cache poisoning, session manipulation, and data exposure. |
| Spring Cloud Gateway Server forwards the X-Forwarded-For and Forwarded headers from untrusted proxies. |
| 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, leading to unauthorized
data access or modification. The main threat from this flaw impacts data
confidentiality and integrity. |
| HTTP request desynchronization in Ping Identity PingAccess, all versions prior to 8.0.1 affected allows an attacker to send specially crafted http header requests to create a request smuggling condition for proxied requests. |
| 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 arbitrary files to directories of their choice, potentially leading to remote code execution or server compromise. |
| Illegal HTTP request traffic vulnerability (CL.0) in Altitude Communication Server, caused by inconsistent analysis of multiple HTTP requests over a single Keep-Alive connection using Content-Length headers. This can cause a desynchronization of requests between frontend and backend servers, which could allow request hiding, cache poisoning or security bypass. |
| 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 through 12.11.2. |
| h11 is a Python implementation of HTTP/1.1. Prior to version 0.16.0, a leniency in h11's parsing of line terminators in chunked-coding message bodies can lead to request smuggling vulnerabilities under certain conditions. This issue has been patched in version 0.16.0. Since exploitation requires the combination of buggy h11 with a buggy (reverse) proxy, fixing either component is sufficient to mitigate this issue. |
| An issue was discovered in Akamai Ghost, as used for the Akamai CDN platform before 2025-03-26. Under certain circumstances, a client making an HTTP/1.x OPTIONS request with an "Expect: 100-continue" header, and using obsolete line folding, can lead to a discrepancy in how two in-path Akamai servers interpret the request, allowing an attacker to smuggle a second request in the original request body. |
| Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in ithewei libhv allows HTTP Response Smuggling.This issue affects libhv: through 1.3.3. |
| A vulnerability was found in the Keycloak Server. The Keycloak Server is vulnerable to a denial of service (DoS) attack due to improper handling of proxy headers. When Keycloak is configured to accept incoming proxy headers, it may accept non-IP values, such as obfuscated identifiers, without proper validation. This issue can lead to costly DNS resolution operations, which an attacker could exploit to tie up IO threads and potentially cause a denial of service.
The attacker must have access to send requests to a Keycloak instance that is configured to accept proxy headers, specifically when reverse proxies do not overwrite incoming headers, and Keycloak is configured to trust these headers. |
| 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 HttpObjectDecoder to transition into a BAD_MESSAGE state. As a result, any subsequent legitimate requests on the same connection are ignored, leading to client timeouts, which may impact systems using load balancers and expose them to risk. |
