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.

INFO

Published Date :

2026-04-13T00:00:00.000Z

Last Modified :

2026-04-22T18:43:17.553Z

Source :

mitre
AFFECTED PRODUCTS

The following products are affected by CVE-2026-33555 vulnerability.

Vendors Products
Haproxy
  • Haproxy
REFERENCES

Here, you will find a curated list of external links that provide in-depth information to CVE-2026-33555.

URL Resource
https://github.com/haproxy/haproxy/commit/05a295441c621089ffa4318daf0dbca2dd756a84 cve-icon cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-33555 cve-icon
https://r3verii.github.io/cve/2026/04/14/haproxy-h3-standalone-fin-smuggling.html cve-icon cve-icon cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-33555 cve-icon
https://www.haproxy.com/documentation/haproxy-aloha/changelog/ cve-icon cve-icon cve-icon
https://www.haproxy.org cve-icon cve-icon cve-icon
https://www.mail-archive.com/[email protected]/msg46752.html cve-icon cve-icon cve-icon
Login to claim this CVE

CVSS Vulnerability Scoring System

Detailed values of each vector for above chart.
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact