{"id":"CVE-2023-40225","url":"https://www.cyber-defence.io/tools/cve/CVE-2023-40225","generatedAt":"2026-10-28T07:25:29.641Z","title":"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.","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.","published":"2023-08-10T21:15:11.000Z","lastModified":"2026-06-17T06:16:50.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.1","score":7.2,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N"},"cwe":["CWE-444"],"affected":["haproxy/haproxy"],"epss":{"score":0.02147,"percentile":0.82011,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (2.15%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://cwe.mitre.org/data/definitions/436.html","tags":["Technical Description"],"source":"cve@mitre.org"},{"url":"https://github.com/haproxy/haproxy/commit/6492f1f29d738457ea9f382aca54537f35f9d856","tags":["Patch"],"source":"cve@mitre.org"},{"url":"https://github.com/haproxy/haproxy/issues/2237","tags":["Exploit","Issue Tracking","Vendor Advisory"],"source":"cve@mitre.org"},{"url":"https://www.haproxy.org/download/2.6/src/CHANGELOG","tags":["Release Notes"],"source":"cve@mitre.org"},{"url":"https://www.haproxy.org/download/2.7/src/CHANGELOG","tags":["Release Notes"],"source":"cve@mitre.org"},{"url":"https://www.haproxy.org/download/2.8/src/CHANGELOG","tags":["Release Notes"],"source":"cve@mitre.org"},{"url":"https://cwe.mitre.org/data/definitions/436.html","tags":["Technical Description"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/haproxy/haproxy/commit/6492f1f29d738457ea9f382aca54537f35f9d856","tags":["Patch"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/haproxy/haproxy/issues/2237","tags":["Exploit","Issue Tracking","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.haproxy.org/download/2.6/src/CHANGELOG","tags":["Release Notes"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.haproxy.org/download/2.7/src/CHANGELOG","tags":["Release Notes"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.haproxy.org/download/2.8/src/CHANGELOG","tags":["Release Notes"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2023-40225","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}