# CVE-2023-25725: haproxy: HAProxy before 2.7.3 may allow a bypass of access control because HTTP/1headers are inadvertently lost in some situat...

CVE-2023-25725 is fixed in 2 products on 1 platform, first by haproxy 1.8.8-1ubuntu0.13, released February 14, 2023. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2023-25725
- Priority: High
- CVSS: 9.1 (Medium)
- EPSS: 0.0549
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Feb 14, 2023

## Description

HAProxy before 2.7.3 may allow a bypass of access control because HTTP/1headers are inadvertently lost in some situations, aka "request smuggling."The HTTP header parsers in HAProxy may accept empty header field names,which could be used to truncate the list of HTTP headers and thus make someheaders disappear after being parsed and processed for HTTP/1.0 andHTTP/1.1. For HTTP/2 and HTTP/3, the impact is limited because the headersdisappear before being parsed and processed, as if they had not been sentby the client. The fixed versions are 2.7.3, 2.6.9, 2.5.12, 2.4.22, 2.2.29,and 2.0.31.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | haproxy Debian 12.15 (bookworm) | 2.6.8-2 | [DEBIAN-CVE-2023-25725](https://patchblox.com/security/data/fix/linux/debian-cve-2023-25725.md) | Feb 14, 2023 |
| Linux | haproxy Debian 13.5 (trixie) | 2.6.8-2 | [DEBIAN-CVE-2023-25725](https://patchblox.com/security/data/fix/linux/debian-cve-2023-25725.md) | Feb 14, 2023 |
| Linux | haproxy Debian 14 | 2.6.8-2 | [DEBIAN-CVE-2023-25725](https://patchblox.com/security/data/fix/linux/debian-cve-2023-25725.md) | Feb 14, 2023 |
| Linux | haproxy RHEL 9 | 0:2.4.17-3.el9_1.2 | [RHSA-2023:1696](https://patchblox.com/security/data/fix/linux/rhsa-2023-1696.md) | Apr 11, 2023 |
| Linux | haproxy Ubuntu 18.04.6 LTS (bionic) | 1.8.8-1ubuntu0.13 | [haproxy 1.8.8-1ubuntu0.13](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-haproxy-1.8.8-1ubuntu0.13.md) | Feb 14, 2023 |
| Linux | haproxy Ubuntu 20.04 LTS (focal) | 2.0.29-0ubuntu1.3 | [haproxy 2.0.29-0ubuntu1.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-haproxy-2.0.29-0ubuntu1.3.md) | Feb 14, 2023 |
| Linux | haproxy Ubuntu 22.04.1 LTS (jammy) | 2.4.18-0ubuntu1.2 | [haproxy 2.4.18-0ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-haproxy-2.4.18-0ubuntu1.2.md) | Feb 14, 2023 |
| Linux | haproxy Ubuntu 24.10 (oracular) | 2.6.9-1ubuntu1 | [haproxy 2.6.9-1ubuntu1](https://patchblox.com/security/data/fix/linux/ubuntu-oracular-haproxy-2.6.9-1ubuntu1.md) | Jan 16, 2026 |
| Linux | haproxy almalinux 9 | 2.4.17-3.el9_1.2 | [ALSA-2023:1696](https://patchblox.com/security/data/fix/linux/alsa-2023-1696.md) | Apr 11, 2023 |
| Linux | haproxy ol 9 | 0:2.4.17-3.el9_1.2 | [ELSA-2023-1696](https://patchblox.com/security/data/fix/linux/elsa-2023-1696.md) | Apr 11, 2023 |
| Linux | vim-haproxy Ubuntu 18.04.6 LTS (bionic) | 1.8.8-1ubuntu0.13 | [vim-haproxy 1.8.8-1ubuntu0.13](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-vim-haproxy-1.8.8-1ubuntu0.13.md) | Feb 14, 2023 |
| Linux | vim-haproxy Ubuntu 20.04 LTS (focal) | 2.0.29-0ubuntu1.3 | [vim-haproxy 2.0.29-0ubuntu1.3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-vim-haproxy-2.0.29-0ubuntu1.3.md) | Feb 14, 2023 |
| Linux | vim-haproxy Ubuntu 22.04.1 LTS (jammy) | 2.4.18-0ubuntu1.2 | [vim-haproxy 2.4.18-0ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-vim-haproxy-2.4.18-0ubuntu1.2.md) | Feb 14, 2023 |
| Linux | vim-haproxy Ubuntu 24.10 (oracular) | 2.6.9-1ubuntu1 | [vim-haproxy 2.6.9-1ubuntu1](https://patchblox.com/security/data/fix/linux/ubuntu-oracular-vim-haproxy-2.6.9-1ubuntu1.md) | Jan 16, 2026 |

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