{"cve":"CVE-2026-47737","nvd":{"published":"2026-07-14T20:17:03.767","modified":"2026-07-15T18:15:13.373","status":"Deferred","description":"Puma is a Ruby/Rack web server built for parallelism. From 5.5.0 until 7.2.1 and 8.0.2, Puma is vulnerable to source IP spoofing when set_remote_address proxy_protocol: :v1 is enabled and persistent connections are used because Puma incorrectly re-parses PROXY protocol headers after each keep-alive request on the same connection, allowing an attacker to inject a second PROXY header and overwrite REMOTE_ADDR. This issue is fixed in versions 7.2.1 and 8.0.2.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","score":7.5},"cwes":["CWE-290","CWE-345"],"references":["https://github.com/puma/puma/commit/439c6136d9c2275721b7864db3ee78af7c80889f","https://github.com/puma/puma/commit/ebe9db3929ab8299d19c8f5b41e8ef4f4b22fa58","https://github.com/puma/puma/pull/3944","https://github.com/puma/puma/pull/3947","https://github.com/puma/puma/releases/tag/v7.2.1"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:45:36.895656543+00:00"},"epss":{"cve":"CVE-2026-47737","score":0.00177,"percentile":0.07306,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-2vqw-3mp8-cgmx","url":"https://osv.dev/vulnerability/GHSA-2vqw-3mp8-cgmx","summary":"Puma PROXY Protocol v1 Accepts Repeated Protocol Headers on Persistent Connections","modified":"2026-09-10T03:51:07.629777089Z","packages":[{"ecosystem":"RubyGems","name":"puma","purl":"pkg:gem/puma","ranges":[">=8.0.0 <8.0.2"],"fixed":["8.0.2"]},{"ecosystem":"RubyGems","name":"puma","purl":"pkg:gem/puma","ranges":[">=5.5.0 <7.2.1"],"fixed":["7.2.1"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}