Denial of Service Vulnerability in HAProxy by HAProxy Technologies
CVE-2026-110354

7.5HIGH

Key Information:

Vendor

Haproxy

Status
Haproxy
Haproxy Enterprise Edition
Haproxy Kubernetes Ingress Controller
Kubernetes Ingress Controller Enterprise
Vendor
CVE Published:
22 October 2026

What is CVE-2026-110354?

A vulnerability exists in HAProxy versions prior to 3.4.6 that allows remote unauthenticated attackers to exploit the software through crafted HTTP/1.1 chunked requests. This can lead to persistent CPU exhaustion of worker threads, causing the affected process to become unresponsive. Although the H1 multiplexer attempts to manage the request, the parser repeatedly reprocesses the same data without advancing, leading to high CPU utilization even after client disconnections or timeouts. Repeated exploitation can deplete worker threads, necessitating a process restart.

Affected Version(s)

HAProxy 3.0.0 < 3.0.30

HAProxy 3.2.0 < 3.2.26

HAProxy 3.3.0 < 3.3.17

References

https://git.haproxy.org/?p=haproxy.git;a=commit;h=077906d...
vendor-advisory

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.