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.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | haproxy | 2.2.16-1 | — |
| Debian 13 | haproxy | 2.2.16-1 | — |
| Debian 12 | haproxy | 2.2.16-1 | — |
| Debian 11 | haproxy | 2.2.9-2+deb11u1 | DSA-4960-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat OpenShift 4 | haproxy | 2.2.13-2.el7 | RHSA-2021:5208, RHSA-2021:4118 |
Advisories 4
- DSA-4960-1 haproxy - security update Debian Security (DSA / DLA) · Mar 9, 2026
- RHSA-2021:5208 Red Hat Security Advisory: OpenShift Container Platform 4.8.25 security update Red Hat Security Advisories (RHSA) · Dec 18, 2025
- RHSA-2021:4118 Red Hat Security Advisory: OpenShift Container Platform 4.9.6 packages and security update Red Hat Security Advisories (RHSA) · Nov 22, 2025
- WID-SEC-2023-2456 Red Hat OpenShift: Mehrere Schwachstellen BSI CERT-Bund (WID) · Sep 27, 2023