CVE-2026-33555

Updated on 13 Apr 2026

Severity

5.8 Medium severity

Details

CVSS score
5.8
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

Overview

About vulnerability

An issue was discovered in HAProxy before 3.3.6. The HTTP/3 parser does not check that the received body length matches a previously announced content-length when the stream is closed via a frame with an empty payload. This can cause desynchronization issues with the backend server and could be used for request smuggling. The earliest affected version is 2.6.

Details

Affected product:
Alpine Linux 3.18 ELS
Affected packages:
haproxy @ 2.6.22

Fixes