HAProxy 3.2 before 3.4.6 allows a remote unauthenticated attacker to cause a denial of service (worker-thread CPU exhaustion) via a truncated HTTP/2 PING frame. h2c_handle_ping in src/mux_h2.c does not check for a short read, unlike the other H2 frame handlers. Because the incomplete frame cannot be processed, its data is never consumed, and the H2 multiplexer tasklet is repeatedly woken by that pending data without making progress. The CPU spins until timeout http-request closes the connection, and an attacker opening many such connections can sustain high CPU usage.

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History

Thu, 22 Oct 2026 12:30:00 +0000

Type Values Removed Values Added
Title Denial of Service via Truncated HTTP/2 PING in HAProxy haproxy: HAProxy: Denial of Service via truncated HTTP/2 PING frame
Weaknesses CWE-835
References
Metrics threat_severity

None

threat_severity

Important


Thu, 22 Oct 2026 11:00:00 +0000

Type Values Removed Values Added
First Time appeared Haproxy
Haproxy haproxy
Haproxy haproxy Enterprise
Haproxy kubernetes Ingress Controller
Haproxy kubernetes Ingress Controller Enterprise
Vendors & Products Haproxy
Haproxy haproxy
Haproxy haproxy Enterprise
Haproxy kubernetes Ingress Controller
Haproxy kubernetes Ingress Controller Enterprise

Thu, 22 Oct 2026 06:00:00 +0000

Type Values Removed Values Added
Title Denial of Service via Truncated HTTP/2 PING in HAProxy

Thu, 22 Oct 2026 03:00:00 +0000

Type Values Removed Values Added
Description HAProxy 3.2 before 3.4.6 allows a remote unauthenticated attacker to cause a denial of service (worker-thread CPU exhaustion) via a truncated HTTP/2 PING frame. h2c_handle_ping in src/mux_h2.c does not check for a short read, unlike the other H2 frame handlers. Because the incomplete frame cannot be processed, its data is never consumed, and the H2 multiplexer tasklet is repeatedly woken by that pending data without making progress. The CPU spins until timeout http-request closes the connection, and an attacker opening many such connections can sustain high CPU usage.
Weaknesses CWE-252
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2026-10-22T19:10:34.428Z

Reserved: 2026-10-13T23:18:04.062Z

Link: CVE-2026-110353

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-22T03:16:31.270

Modified: 2026-10-22T19:17:35.540

Link: CVE-2026-110353

cve-icon Redhat

Severity : Important

Publid Date: 2026-10-22T02:53:33Z

Links: CVE-2026-110353 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-10-22T15:45:08Z

Weaknesses