HAProxy High Performance TCP/HTTP Load Balancer
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Products by HAProxy Sorted by Most Security Vulnerabilities since 2018
By the Year
In 2025 there have been 0 vulnerabilities in HAProxy. Last year, in 2024 HAProxy had 1 security vulnerability published. Right now, HAProxy is on track to have less security vulnerabilities in 2025 than it did last year.
| Year | Vulnerabilities | Average Score |
|---|---|---|
| 2025 | 0 | 0.00 |
| 2024 | 1 | 7.50 |
| 2023 | 6 | 7.63 |
| 2022 | 1 | 7.50 |
| 2021 | 4 | 6.95 |
| 2020 | 1 | 8.80 |
| 2019 | 6 | 7.62 |
| 2018 | 5 | 7.18 |
It may take a day or so for new HAProxy vulnerabilities to show up in the stats or in the list of recent security vulnerabilties. Additionally vulnerabilities may be tagged under a different product or component name.
Recent HAProxy Security Vulnerabilities
HAProxy 2.9.x before 2.9.10, 3.0.x before 3.0.4, and 3.1.x through 3.1-dev6
CVE-2024-45506
7.5 - High
- September 04, 2024
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.
HAProxy before 2.8.2 accepts # as part of the URI component, which might
CVE-2023-45539
8.2 - High
- November 28, 2023
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.
HAProxy through 2.0.32
CVE-2023-40225
7.2 - High
- August 10, 2023
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 extra request.
HTTP Request Smuggling
HTTP request/response smuggling vulnerability in HAProxy version 2.7.0, and 2.6.1 to 2.6.7
CVE-2023-25950
7.3 - High
- April 11, 2023
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.
HTTP Request Smuggling
An information leak vulnerability was discovered in HAProxy 2.1
CVE-2023-0836
7.5 - High
- March 29, 2023
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 FastCGI backends in an unexpected way.
Information Disclosure
An uncontrolled resource consumption vulnerability was discovered in HAProxy which could crash the service
CVE-2023-0056
6.5 - Medium
- March 23, 2023
An uncontrolled resource consumption vulnerability was discovered in HAProxy which could crash the service. This issue could allow an authenticated remote attacker to run a specially crafted malicious server in an OpenShift cluster. The biggest impact is to availability.
Resource Exhaustion
HAProxy before 2.7.3 may
CVE-2023-25725
9.1 - Critical
- February 14, 2023
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 being parsed and processed for HTTP/1.0 and HTTP/1.1. For HTTP/2 and HTTP/3, the impact is limited because the headers disappear before being parsed and processed, as if they had not been sent by the client. The fixed versions are 2.7.3, 2.6.9, 2.5.12, 2.4.22, 2.2.29, and 2.0.31.
A flaw was found in the way HAProxy processed HTTP responses containing the "Set-Cookie2" header
CVE-2022-0711
7.5 - High
- March 02, 2022
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.
Infinite Loop
An integer overflow exists in HAProxy 2.0 through 2.5 in htx_add_header
CVE-2021-40346
7.5 - High
- September 08, 2021
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.
Integer Overflow or Wraparound
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
CVE-2021-39242
7.5 - High
- August 17, 2021
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.
Improper Handling of Exceptional Conditions