| CVE-2026-26081 | MEDIO4.8 | HAProxy Community Edition 3.0 through 3.3 before 3.3.3 lacks a length check for the NEW_TOKEN format. HAProxy Enterprise and ALOHA are also affected. | 20/07/2026 |
| CVE-2026-26080 | BAJO3.7 | HAProxy Community Edition 3.2.x through 3.3.x before 3.3.3 can enter a loop or crash because varint is mishandled. HAProxy Enterprise and ALOHA are also affected. | 20/07/2026 |
| CVE-2026-55204 | ALTO7.5 | HAProxy through 3.4.0, fixed in commit 9a6d1fe, contains a null pointer dereference vulnerability in hpack_dht_insert() within src/hpack-tbl.c that fails to validate the return value of hpack_dht_defrag() when the memory pool is exhausted. An attacker can trigger HPACK dynamic table insertions under memory pressure to | 18/06/2026 |
| CVE-2026-55203 | CRÍTICO9.1 | HAProxy through 3.4.0, fixed in commit 5985276, contains an integer overflow vulnerability in the fcgi_conn structure's drl field that allows buffer misparse as new FCGI record headers. When contentLength is 65535 and paddingLength is 1 or more, the drl field wraps to 0, causing incorrect record consumption and allowin | 18/06/2026 |
| CVE-2026-33555 | MEDIO5.8 | An issue was discovered in HAProxy before 3.3.6. The HTTP/3 parser does not check that the received body length matches a previously announced content-length when the stream is closed via a frame with an empty payload. This can cause desynchronization issues with the backend server and could be used for request smuggli | 13/04/2026 |
| CVE-2025-11230 | ALTO7.5 | Inefficient algorithm complexity in mjson in HAProxy allows remote attackers to cause a denial of service via specially crafted JSON requests. | 19/11/2025 |
| CVE-2024-45506 | ALTO7.5 | HAProxy 2.9.x before 2.9.10, 3.0.x before 3.0.4, and 3.1.x through 3.1-dev6 allows a remote denial of service for HTTP/2 zero-copy forwarding (h2_send loop) under a certain set of conditions, as exploited in the wild in 2024. | 04/09/2024 |
| CVE-2023-45539 | ALTO8.2 | HAProxy before 2.8.2 accepts # as part of the URI component, which might allow remote attackers to obtain sensitive information or have unspecified other impact upon misinterpretation of a path_end rule, such as routing index.html#.png to a static server. | 28/11/2023 |
| CVE-2023-40225 | ALTO7.2 | HAProxy through 2.0.32, 2.1.x and 2.2.x through 2.2.30, 2.3.x and 2.4.x through 2.4.23, 2.5.x and 2.6.x before 2.6.15, 2.7.x before 2.7.10, and 2.8.x before 2.8.2 forwards empty Content-Length headers, violating RFC 9110 section 8.6. In uncommon cases, an HTTP/1 server behind HAProxy may interpret the payload as an ext | 10/08/2023 |
| CVE-2023-25950 | ALTO7.3 | 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. | 11/04/2023 |
| CVE-2023-0836 | ALTO7.5 | An information leak vulnerability was discovered in HAProxy 2.1, 2.2 before 2.2.27, 2.3, 2.4 before 2.4.21, 2.5 before 2.5.11, 2.6 before 2.6.8, 2.7 before 2.7.1. There are 5 bytes left uninitialized in the connection buffer when encoding the FCGI_BEGIN_REQUEST record. Sensitive data may be disclosed to configured Fast | 29/03/2023 |
| CVE-2023-25725 | CRÍTICO9.1 | 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 | 14/02/2023 |
| CVE-2022-0711 | ALTO7.5 | A flaw was found in the way HAProxy processed HTTP responses containing the "Set-Cookie2" header. This flaw could allow an attacker to send crafted HTTP response packets which lead to an infinite loop, eventually resulting in a denial of service condition. The highest threat from this vulnerability is availability. | 02/03/2022 |
| CVE-2021-40346 | ALTO7.5 | An integer overflow exists in HAProxy 2.0 through 2.5 in htx_add_header that can be exploited to perform an HTTP request smuggling attack, allowing an attacker to bypass all configured http-request HAProxy ACLs and possibly other ACLs. | 08/09/2021 |
| CVE-2021-39242 | ALTO7.5 | An issue was discovered in HAProxy 2.2 before 2.2.16, 2.3 before 2.3.13, and 2.4 before 2.4.3. It can lead to a situation with an attacker-controlled HTTP Host header, because a mismatch between Host and authority is mishandled. | 17/08/2021 |
| CVE-2021-39241 | MEDIO5.3 | An issue was discovered in HAProxy 2.0 before 2.0.24, 2.2 before 2.2.16, 2.3 before 2.3.13, and 2.4 before 2.4.3. An HTTP method name may contain a space followed by the name of a protected resource. It is possible that a server would interpret this as a request for that protected resource, such as in the "GET /admin? | 17/08/2021 |
| CVE-2021-39240 | ALTO7.5 | An issue was discovered in HAProxy 2.2 before 2.2.16, 2.3 before 2.3.13, and 2.4 before 2.4.3. It does not ensure that the scheme and path portions of a URI have the expected characters. For example, the authority field (as observed on a target HTTP/2 server) might differ from what the routing rules were intended to ac | 17/08/2021 |
| CVE-2020-11100 | ALTO8.8 | In hpack_dht_insert in hpack-tbl.c in the HPACK decoder in HAProxy 1.8 through 2.x before 2.1.4, a remote attacker can write arbitrary bytes around a certain location on the heap via a crafted HTTP/2 request, possibly causing remote code execution. | 02/04/2020 |
| CVE-2019-19330 | CRÍTICO9.8 | The HTTP/2 implementation in HAProxy before 2.0.10 mishandles headers, as demonstrated by carriage return (CR, ASCII 0xd), line feed (LF, ASCII 0xa), and the zero character (NUL, ASCII 0x0), aka Intermediary Encapsulation Attacks. | 27/11/2019 |
| CVE-2019-18277 | ALTO7.5 | A flaw was found in HAProxy before 2.0.6. In legacy mode, messages featuring a transfer-encoding header missing the "chunked" value were not being correctly rejected. The impact was limited but if combined with the "http-reuse always" setting, it could be used to help construct an HTTP request smuggling attack against | 23/10/2019 |