Critical DoS Vulnerability Discovered in HAProxy Load Balancer

A vulnerability was discovered in HAProxy, a widely used open-source load balancer and reverse proxy. The flaw allows a remote attacker to trigger a denial-of-service (DoS) condition. The security notice was published on June 29, 2026, by the French National Cybersecurity Agency (ANSSI) via its CERT-FR team. No specific CVE identifier, affected versions, or technical details about the exploitation mechanism were provided in the notice. The impact is limited to service disruption rather than code execution or data compromise.