HOMEVULNERABILITIESCVE-2023-40225
HIGH

CVE-2023-40225

CWE-444Published: August 10, 2023· Updated: Jun 17, 2026

7.2
CVSS v3.1

Official Description

HAProxy through 2.0.32, 2.1.x and 2.2.x through 2.2.30, 2.3.x and 2.4.x through 2.4.23, 2.5.x and 2.6.x before 2.6.15, 2.7.x before 2.7.10, and 2.8.x before 2.8.2 forwards empty Content-Length headers, violating RFC 9110 section 8.6. In uncommon cases, an HTTP/1 server behind HAProxy may interpret the payload as an extra request.

NVD Source

Technical Analysis

CVE-2023-40225 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeChanged
Impact
ConfidentialityLow
IntegrityLow
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

Affected Vendors & Products

haproxy1 product(s)
haproxy
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://github.com/haproxy/haproxy/commit/6492f1f29d738457ea9f382aca54537f35f9d856
PATCHhttps://github.com/haproxy/haproxy/commit/6492f1f29d738457ea9f382aca54537f35f9d856
ADVISORYhttps://github.com/haproxy/haproxy/issues/2237
ADVISORYhttps://github.com/haproxy/haproxy/issues/2237

All References (12)

→
https://cwe.mitre.org/data/definitions/436.htmlTechnical Description
→
https://github.com/haproxy/haproxy/commit/6492f1f29d738457ea9f382aca54537f35f9d856Patch
→
https://github.com/haproxy/haproxy/issues/2237Exploit · Issue Tracking · Vendor Advisory
→
https://www.haproxy.org/download/2.6/src/CHANGELOGRelease Notes
→
https://www.haproxy.org/download/2.7/src/CHANGELOGRelease Notes
→
https://www.haproxy.org/download/2.8/src/CHANGELOGRelease Notes
→
https://cwe.mitre.org/data/definitions/436.htmlTechnical Description
→
https://github.com/haproxy/haproxy/commit/6492f1f29d738457ea9f382aca54537f35f9d856Patch
→
https://github.com/haproxy/haproxy/issues/2237Exploit · Issue Tracking · Vendor Advisory
→
https://www.haproxy.org/download/2.6/src/CHANGELOGRelease Notes
→
https://www.haproxy.org/download/2.7/src/CHANGELOGRelease Notes
→
https://www.haproxy.org/download/2.8/src/CHANGELOGRelease Notes

Quick Facts

CVE IDCVE-2023-40225
CVSS Score7.2 / 10
SeverityHIGH
WeaknessCWE-444
CISA KEVNo
Affected1 vendor(s)
PublishedAug 10, 2023

Related CVEs (CWE-444)

CVE-2025-1867
10.0
CVE-2018-3907
10.0
CVE-2025-55315
9.9
CVE-2026-11541
9.8
CVE-2026-13763
9.8
CVE-2026-13762
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Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2023-40225 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWatch. CVE data is provided under the NVD usage policy.
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