CVE-2026-33555

Published Apr 13, 2026

Last updated a month ago

Overview

Description
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.
Source
cve@mitre.org
NVD status
Analyzed
Products
haproxy

Risk scores

CVSS 3.1

Type
Primary
Base score
5.8
Impact score
1.4
Exploitability score
3.9
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
Severity
MEDIUM

Weaknesses

cve@mitre.org
CWE-130

Social media

Hype score
Not currently trending

Configurations