CVE Database · CVE-2026-33555
CVSS v3.1
4.0
EPSS
0.30%
Published
Apr 13, 2026
Modified
Apr 22, 2026
Public PoC / Exploit (1)
All weaponized →Links to public security research (Exploit-DB, Nuclei, Trickest, GitHub) for defensive use only.
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.
CVSS Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:NWeaknesses (CWE)
References (6)