CVE-2021-39242

HIGH

HAProxy 2.2.0-2.2.15, 2.3.0-2.3.12, 2.4.0-2.4.2 - HTTP Host Header Handling Issue

Title source: llm
STIX 2.1

Description

An issue was discovered in HAProxy 2.2 before 2.2.16, 2.3 before 2.3.13, and 2.4 before 2.4.3. It can lead to a situation with an attacker-controlled HTTP Host header, because a mismatch between Host and authority is mishandled.

Scores

CVSS v3 7.5
EPSS 0.0047
EPSS Percentile 64.7%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Details

CWE
CWE-755
Status published
Products (4)
debian/debian_linux 11.0
fedoraproject/fedora 33
fedoraproject/fedora 34
haproxy/haproxy 2.2.0 - 2.2.16
Published Aug 17, 2021
Tracked Since Feb 18, 2026