CVE-2026-33555
Fixed in a distro release EPSS <1%CVSS 4.0
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.
Products: haproxy
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| Chainguard | haproxy-2.6 | 2.6.31-r0 |
| Chainguard | haproxy-2.8 | 2.8.26-r0 |
| Chainguard | haproxy-3.0 | 3.0.19-r0 |
| Chainguard | haproxy-3.1 | no fix |
| Chainguard | haproxy-3.2 | 3.2.15-r0 |
| Debian 12 | haproxy | 2.6.12-1+deb12u4 |
| Debian 13 | haproxy | 3.0.11-1+deb13u3 |
| Debian 14 | haproxy | 3.2.15-1 |
| Red Hat hummingbird 1 | haproxy | 0:3.0.19-1.1.hum1 |
| SUSE Linux Enterprise High Availability Extension 15 SP6 | haproxy | 2.8.11+git0.01c1056a4-150600.3.12.1 |
| SUSE Linux Enterprise High Availability Extension 15 SP7 | haproxy | 2.8.11+git0.01c1056a4-150600.3.12.1 |
| SUSE Linux Micro 6.2 | haproxy | 3.2.15+git64.0fc44b458-160000.2.1 |
| Ubuntu 24.04 LTS | haproxy | 2.8.16-0ubuntu0.24.04.2 |
| Ubuntu 25.10 | haproxy | 3.0.12-0ubuntu0.25.10.4 |
| Ubuntu 26.04 LTS | haproxy | 3.2.9-1ubuntu2.1 |
| Wolfi | haproxy-3.2 | 3.2.15-r0 |
| openSUSE Leap 16.0 | haproxy | 3.2.15+git64.0fc44b458-160000.2.1 |
| openSUSE Tumbleweed | haproxy | 3.3.6+git91.af5637e93-1.1 |