| Name | CVE-2026-55203 |
| Description | HAProxy through 3.4.0, fixed in commit 5985276, contains an integer overflow vulnerability in the fcgi_conn structure's drl field that allows buffer misparse as new FCGI record headers. When contentLength is 65535 and paddingLength is 1 or more, the drl field wraps to 0, causing incorrect record consumption and allowing malicious FastCGI backends to desynchronize the FCGI framing parser, potentially causing request routing errors, response smuggling, or memory safety issues. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| Debian Bugs | 1140430 |
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| haproxy (PTS) | bullseye | 2.2.9-2+deb11u6 | vulnerable |
| bullseye (security) | 2.2.9-2+deb11u7 | vulnerable | |
| bookworm, bookworm (security) | 2.6.12-1+deb12u3 | vulnerable | |
| trixie | 3.0.11-1+deb13u2 | vulnerable | |
| trixie (security) | 3.0.11-1+deb13u3 | vulnerable | |
| forky, sid | 3.2.21-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| haproxy | source | experimental | 3.4.1-1 | |||
| haproxy | source | (unstable) | 3.2.20-1 | 1140430 |
[trixie] - haproxy <no-dsa> (Minor issue)
https://github.com/haproxy/haproxy/commit/5985276735777634d8c85f1d73bb7764aab0d6dd