{"id":"CVE-2026-110354","title":"HAProxy 3 before 3.4.6 allows a remote unauthenticated attacker to cause a denial of service (persistent worker-thread CPU exhaustion) via an HTTP/1.1 chunked request","summary":"HAProxy 3 before 3.4.6 allows a remote unauthenticated attacker to cause a denial of service (persistent worker-thread CPU exhaustion) via an HTTP/1.1 chunked request. Although the H1 multiplexer drains the request before closing the str…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvssSource":"cna","cwe":["CWE-835"],"vendor":"HAProxy","product":"HAProxy","affected":["HAProxy >= 3.0.0 < 3.0.30","HAProxy >= 3.2.0 < 3.2.26","HAProxy >= 3.3.0 < 3.3.17","HAProxy >= 3.4.0 < 3.4.6","HAProxy >= 3.5-dev < 3.5-dev9","enterprise_edition >= 3.0r1 < 3.0r1-362.1441","enterprise_edition >= 3.2r1 < 3.2r1-378.1259","enterprise_edition >= 3.3r1 < 3.3r1-377.1005","haproxy_kubernetes_ingress_controller >= 3.2.0 < 3.2.17","kubernetes_ingress_controller_enterprise >= 3.2.0 < 3.2.17-ee1","kubernetes_ingress_controller_enterprise >= 3.0 < 3.0.16-ee17","kubernetes_ingress_controller_enterprise >= 1.11 < 1.11.14-ee11"],"published":"2026-10-22","updated":"2026-10-22","sourceUpdated":"2026-10-22T02:46:38.255Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-110354","references":[{"url":"https://git.haproxy.org/?p=haproxy.git;a=commit;h=077906da140a35873bf451d7e9f67646c9f37c81"}],"tags":["cve.org"],"ingestedAt":"2026-10-22T03:25:15.658Z","slug":"CVE-2026-110354","body":"## Overview\n\nHAProxy 3 before 3.4.6 allows a remote unauthenticated attacker to cause a denial of service (persistent worker-thread CPU exhaustion) via an HTTP/1.1 chunked request. Although the H1 multiplexer drains the request before closing the stream, the parser repeatedly re-processes the same bytes without making progress. The affected thread stays busy at 100% CPU after timeouts expire and after the client disconnects, and repeated requests can consume all worker threads until the process is restarted.\n\n## Affected\n\n- `HAProxy >= 3.0.0 < 3.0.30`\n- `HAProxy >= 3.2.0 < 3.2.26`\n- `HAProxy >= 3.3.0 < 3.3.17`\n- `HAProxy >= 3.4.0 < 3.4.6`\n- `HAProxy >= 3.5-dev < 3.5-dev9`\n- `enterprise_edition >= 3.0r1 < 3.0r1-362.1441`\n- `enterprise_edition >= 3.2r1 < 3.2r1-378.1259`\n- `enterprise_edition >= 3.3r1 < 3.3r1-377.1005`\n- `haproxy_kubernetes_ingress_controller >= 3.2.0 < 3.2.17`\n- `kubernetes_ingress_controller_enterprise >= 3.2.0 < 3.2.17-ee1`\n- `kubernetes_ingress_controller_enterprise >= 3.0 < 3.0.16-ee17`\n- `kubernetes_ingress_controller_enterprise >= 1.11 < 1.11.14-ee11`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}