CVE catalog
CVE-2026-33555
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
- Severity
- Medium · CVSS 4
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.31% · Oct 25, 2026
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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | haproxy | sid | 3.2.26-1 | fixed |
| Debian | haproxy | forky | 3.2.26-1 | fixed |
| Debian | haproxy | trixie | 3.0.11-1+deb13u3 | fixed |
| Debian | haproxy | trixie-security | 3.0.11-1+deb13u4 | fixed |
| Debian | haproxy | bookworm | 2.6.12-1+deb12u3 | vulnerable |
| Debian | haproxy | bookworm-security | 2.6.12-1+deb12u4 | fixed |
| Cpe | haproxy | Not reported | Not reported | vulnerable |
| Cpe | haproxy | Not reported | 3.3.6 | fixed |
| Cpe | haproxy | Not reported | 3.3.6 | fixed |
| Ubuntu | haproxy | 24.04 | 2.6.15-1ubuntu2 | vulnerable |
| Ubuntu | haproxy | 24.04 | 2.8.5-1ubuntu1 | vulnerable |
| Ubuntu | haproxy | 24.04 | 2.8.5-1ubuntu2 | vulnerable |
| Ubuntu | haproxy | 24.04 | 2.8.5-1ubuntu3 | vulnerable |
| Ubuntu | haproxy | 24.04 | 2.8.5-1ubuntu3.1 | vulnerable |
| Ubuntu | haproxy | 24.04 | 2.8.5-1ubuntu3.2 | vulnerable |
| Ubuntu | haproxy | 24.04 | 2.8.5-1ubuntu3.3 | vulnerable |
| Ubuntu | haproxy | 24.04 | 2.8.5-1ubuntu3.4 | vulnerable |
| Ubuntu | haproxy | 24.04 | 2.8.15-0ubuntu0.24.04.1 | vulnerable |
| Ubuntu | haproxy | 24.04 | 2.8.16-0ubuntu0.24.04.1 | vulnerable |
| Ubuntu | haproxy | 24.04 | 2.8.16-0ubuntu0.24.04.2 | fixed |
| Ubuntu | haproxy | 25.10 | 3.0.8-1ubuntu1 | vulnerable |
| Ubuntu | haproxy | 25.10 | 3.0.8-1ubuntu1.1 | vulnerable |
| Ubuntu | haproxy | 25.10 | 3.0.10-1ubuntu1 | vulnerable |
| Ubuntu | haproxy | 25.10 | 3.0.10-1ubuntu2 | vulnerable |
| Ubuntu | haproxy | 25.10 | 3.0.10-1ubuntu3 | vulnerable |
| Ubuntu | haproxy | 25.10 | 3.0.12-0ubuntu0.25.10.1 | vulnerable |
| Ubuntu | haproxy | 25.10 | 3.0.12-0ubuntu0.25.10.3 | vulnerable |
| Ubuntu | haproxy | 25.10 | 3.0.12-0ubuntu0.25.10.4 | fixed |
| Ubuntu | haproxy | 26.04 | 3.0.10-1ubuntu3 | vulnerable |
| Ubuntu | haproxy | 26.04 | 3.2.9-1ubuntu1 | vulnerable |
| Ubuntu | haproxy | 26.04 | 3.2.9-1ubuntu2 | vulnerable |
| Ubuntu | haproxy | 26.04 | 3.2.9-1ubuntu2.1 | fixed |
| Opensuse | haproxy | leap 16.0 | 3.2.15+git64.0fc44b458-160000.2.1 | fixed |
| Suse | haproxy | linux micro 6.2 | 3.2.15+git64.0fc44b458-160000.2.1 | fixed |
| Suse | haproxy | linux enterprise high availability extension 15 sp6 | 2.8.11+git0.01c1056a4-150600.3.12.1 | fixed |
| Suse | haproxy | linux enterprise high availability extension 15 sp7 | 2.8.11+git0.01c1056a4-150600.3.12.1 | fixed |
| Opensuse | haproxy | tumbleweed | 3.3.6+git91.af5637e93-1.1 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | haproxy | source | sid | 3.2.15-1 | not yet assigned | Not reported | Not reported |
| Debian | haproxy | source | forky | 3.2.15-1 | not yet assigned | Not reported | Not reported |
| Debian | haproxy | source | trixie | 3.0.11-1+deb13u3 | not yet assigned | Not reported | Not reported |
| Debian | haproxy | source | bookworm | 2.6.12-1+deb12u4 | not yet assigned | Not reported | Not reported |
| Cpe | haproxy | cpe | Not reported | 3.3.6 | Not reported | Not reported | Not reported |
| Cpe | haproxy | cpe | Not reported | 3.3.6 | Not reported | NVD-CVE-2026-33555 | Not reported |
| Ubuntu | haproxy | deb | 24.04 | 2.8.16-0ubuntu0.24.04.2 | Not reported | UBUNTU-CVE-2026-33555 | Not reported |
| Ubuntu | haproxy | deb | 25.10 | 3.0.12-0ubuntu0.25.10.4 | Not reported | UBUNTU-CVE-2026-33555 | Not reported |
| Ubuntu | haproxy | deb | 26.04 | 3.2.9-1ubuntu2.1 | Not reported | UBUNTU-CVE-2026-33555 | Not reported |
| Opensuse | haproxy | rpm | leap 16.0 | 3.2.15+git64.0fc44b458-160000.2.1 | Not reported | OPENSUSE-SU-2026:20618-1 | Not reported |
| Suse | haproxy | rpm | linux micro 6.2 | 3.2.15+git64.0fc44b458-160000.2.1 | Not reported | SUSE-SU-2026:21280-1 | Not reported |
| Suse | haproxy | rpm | linux enterprise high availability extension 15 sp6 | 2.8.11+git0.01c1056a4-150600.3.12.1 | Not reported | SUSE-SU-2026:1568-1 | Not reported |
| Suse | haproxy | rpm | linux enterprise high availability extension 15 sp7 | 2.8.11+git0.01c1056a4-150600.3.12.1 | Not reported | SUSE-SU-2026:1568-1 | Not reported |
| Opensuse | haproxy | rpm | tumbleweed | 3.3.6+git91.af5637e93-1.1 | Not reported | OPENSUSE-SU-2026:10581-1 | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [haproxy]Affected
Details (4)
2.6.12-1+deb12u3· amd64 · bookwormAffected · Fixed:
2.6.12-1+deb12u4nvd · haproxy · debian · bookworm; nvd · haproxy · debian · 12
2.6.12-1+deb12u3· arm64 · bookwormAffected · Fixed:
2.6.12-1+deb12u4nvd · haproxy · debian · bookworm; nvd · haproxy · debian · 12
2.6.12-1+deb12u3· amd64 · bookworm-securityAffected · Fixed:
2.6.12-1+deb12u4nvd · haproxy · debian · bookworm; nvd · haproxy · debian · 12
2.6.12-1+deb12u3· arm64 · bookworm-securityAffected · Fixed:
2.6.12-1+deb12u4nvd · haproxy · debian · bookworm; nvd · haproxy · debian · 12
- [haproxy-doc]Affected
Source package: [haproxy]
Details (4)
2.6.12-1+deb12u3· all · bookwormAffected · Fixed:
2.6.12-1+deb12u4nvd · haproxy · debian · bookworm; nvd · haproxy · debian · 12
2.6.12-1+deb12u3· all · bookwormAffected · Fixed:
2.6.12-1+deb12u4nvd · haproxy · debian · bookworm; nvd · haproxy · debian · 12
2.6.12-1+deb12u3· all · bookworm-securityAffected · Fixed:
2.6.12-1+deb12u4nvd · haproxy · debian · bookworm; nvd · haproxy · debian · 12
2.6.12-1+deb12u3· all · bookworm-securityAffected · Fixed:
2.6.12-1+deb12u4nvd · haproxy · debian · bookworm; nvd · haproxy · debian · 12
- [vim-haproxy]Affected
Source package: [haproxy]
Details (4)
2.6.12-1+deb12u3· all · bookwormAffected · Fixed:
2.6.12-1+deb12u4nvd · haproxy · debian · bookworm; nvd · haproxy · debian · 12
2.6.12-1+deb12u3· all · bookwormAffected · Fixed:
2.6.12-1+deb12u4nvd · haproxy · debian · bookworm; nvd · haproxy · debian · 12
2.6.12-1+deb12u3· all · bookworm-securityAffected · Fixed:
2.6.12-1+deb12u4nvd · haproxy · debian · bookworm; nvd · haproxy · debian · 12
2.6.12-1+deb12u3· all · bookworm-securityAffected · Fixed:
2.6.12-1+deb12u4nvd · haproxy · debian · bookworm; nvd · haproxy · debian · 12
[Debian 13 (Trixie)]
- [haproxy]Fixed
Details (5)
3.0.11-1+deb13u3· amd64 · trixieFixed · Fixed:
3.0.11-1+deb13u3nvd · haproxy · debian · 13
3.0.11-1+deb13u3· arm64 · trixieFixed · Fixed:
3.0.11-1+deb13u3nvd · haproxy · debian · 13
3.0.11-1+deb13u3· amd64 · trixie-security · Historical versionFixed · Fixed:
3.0.11-1+deb13u3nvd · haproxy · debian · 13
3.0.11-1+deb13u3· arm64 · trixie-securityFixed · Fixed:
3.0.11-1+deb13u3nvd · haproxy · debian · 13
3.0.11-1+deb13u4· amd64 · trixie-securityFixed · Fixed:
3.0.11-1+deb13u3nvd · haproxy · debian · 13
- [haproxy-doc]Fixed
Source package: [haproxy]
Details (5)
3.0.11-1+deb13u3· all · trixieFixed · Fixed:
3.0.11-1+deb13u3nvd · haproxy · debian · 13
3.0.11-1+deb13u3· all · trixieFixed · Fixed:
3.0.11-1+deb13u3nvd · haproxy · debian · 13
3.0.11-1+deb13u3· all · trixie-securityFixed · Fixed:
3.0.11-1+deb13u3nvd · haproxy · debian · 13
3.0.11-1+deb13u3· all · trixie-security · Historical versionFixed · Fixed:
3.0.11-1+deb13u3nvd · haproxy · debian · 13
3.0.11-1+deb13u4· all · trixie-securityFixed · Fixed:
3.0.11-1+deb13u3nvd · haproxy · debian · 13
- [vim-haproxy]Fixed
Source package: [haproxy]
Details (5)
3.0.11-1+deb13u3· all · trixieFixed · Fixed:
3.0.11-1+deb13u3nvd · haproxy · debian · 13
3.0.11-1+deb13u3· all · trixieFixed · Fixed:
3.0.11-1+deb13u3nvd · haproxy · debian · 13
3.0.11-1+deb13u3· all · trixie-securityFixed · Fixed:
3.0.11-1+deb13u3nvd · haproxy · debian · 13
3.0.11-1+deb13u3· all · trixie-security · Historical versionFixed · Fixed:
3.0.11-1+deb13u3nvd · haproxy · debian · 13
3.0.11-1+deb13u4· all · trixie-securityFixed · Fixed:
3.0.11-1+deb13u3nvd · haproxy · debian · 13
[openSUSE Tumbleweed]
Observed:
References
- [https://ftp.suse.com/pub/projects/security/]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-33555]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-33555]
- [https://osv.dev/vulnerability/SUSE-SU-2026:1568-1]
- [https://osv.dev/vulnerability/SUSE-SU-2026:21280-1]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2026-33555]
- [https://osv.dev/vulnerability/openSUSE-SU-2026:10581-1]
- [https://osv.dev/vulnerability/openSUSE-SU-2026:20618-1]
- [https://security-tracker.debian.org/tracker/CVE-2026-33555]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33555.json]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-1074.json]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]