CVE-2023-25725

What it is

HAProxy before 2.7.3 may allow a bypass of access control because HTTP/1 headers 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 some headers disappear after being parsed and processed for HTTP/1.0 and HTTP/1.1. For HTTP/2 and HTTP/3, the impact is limited because the headers disappear before being parsed and processed, as if they had not been sent by 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.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data tampering, service disruption.

Exploit odds

5.5% chance of exploitation in the next 30 days (EPSS).

Fix

No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

1. 2023-02-13 00:00 UTC ReservedThe CVE id was reserved by its CNA
2. 2023-02-14 19:15 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-06-17 05:41 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 5.5% in the next 30 days (EPSS).
• Severity: 9.1 CRITICAL (CVSS).
• Fix: none linked yet, which raises it.

Details

Published

2023-02-14 19:15 UTC

Last modified

2026-06-17 05:41 UTC

Exploit probability

5.5% · EPSS, next 30 days

Weakness

CWE-444

Record status

Modified

Affected

• Haproxy < 2.0.31
• Haproxy < 2.2.29
• Haproxy < 2.4.22
• Haproxy < 2.5.12
• Haproxy < 2.6.9
• Haproxy < 2.7.3
• Debian Linux 10.0
• Debian Linux 11.0

Attack profile CVSS 3.1 · 9.1

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2023-25725.md and follow it. Check whether this project is affected by CVE-2023-25725. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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