{"id":"CVE-2026-47737","aliases":["DEBIAN-CVE-2026-47737","EUVD-2026-44427","GHSA-2vqw-3mp8-cgmx","UBUNTU-CVE-2026-47737"],"status":"published","title":"Puma PROXY Protocol v1 Accepts Repeated Protocol Headers on Persistent Connections","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.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00177,"percentile":0.0734,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-290","CWE-345"],"published":"2026-06-09T00:09:44Z","modified":"2026-11-08T02:47:37Z","fixes":[{"ecosystem":"RubyGems","package":"puma","fixed_in":["8.0.2","7.2.1"],"sources":["ghsa","osv"]},{"ecosystem":"Debian:12","package":"puma","fixed_in":["5.6.5-3+deb12u2"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"puma","fixed_in":["8.0.2-1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"RubyGems","package":"puma","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"8.0.0"},{"fixed":"8.0.2"}]}]},{"source":"ghsa","ecosystem":"RubyGems","package":"puma","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.5.0"},{"fixed":"7.2.1"}]}]},{"source":"osv","ecosystem":"Debian:12","package":"puma","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.6.5-3+deb12u2"}]}],"versions":["5.6.5-3","5.6.5-3+deb12u1"]},{"source":"osv","ecosystem":"Debian:13","package":"puma","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["6.6.0-4","8.0.2-1","8.0.2-2","8.0.2-3"]},{"source":"osv","ecosystem":"Debian:14","package":"puma","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"8.0.2-1"}]}],"versions":["6.6.0-4"]},{"source":"osv","ecosystem":"RubyGems","package":"puma","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"8.0.0"},{"fixed":"8.0.2"}]}],"versions":["8.0.0","8.0.1"]},{"source":"osv","ecosystem":"RubyGems","package":"puma","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.5.0"},{"fixed":"7.2.1"}]}],"versions":["5.5.0","5.5.1","5.5.2","5.6.0","5.6.1","5.6.2","5.6.4","5.6.5","5.6.6","5.6.7","5.6.8","5.6.9","6.0.0","6.0.1","6.0.2","6.1.0","6.1.1","6.2.0","6.2.1","6.2.2","6.3.0","6.3.1","6.4.0","6.4.1","6.4.2","6.4.3","6.5.0","6.6.0","6.6.1","7.0.0","7.0.0.pre1","7.0.1","7.0.2","7.0.3","7.0.4","7.1.0","7.2.0"]},{"source":"osv","ecosystem":"Ubuntu:Pro:20.04:LTS","package":"puma","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.12.0-2ubuntu1","3.12.0-4ubuntu1","3.12.4-1ubuntu2","3.12.4-1ubuntu2+esm1","3.12.4-1ubuntu2+esm2"]},{"source":"osv","ecosystem":"Ubuntu:Pro:22.04:LTS","package":"puma","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.3.6-1ubuntu4","5.5.2-2ubuntu2","5.5.2-2ubuntu2+esm1","5.5.2-2ubuntu2+esm2"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"puma","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.6.5-4ubuntu2","5.6.5-4ubuntu3","6.4.2-4ubuntu1","6.4.2-4ubuntu3","6.4.2-4ubuntu4","6.4.2-4ubuntu4.3"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"puma","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["6.6.0-4build1","8.0.2-3build1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"puma","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["6.6.0-4","6.6.0-4build1"]}],"products":[{"vendor":"puma","product":"puma"}],"references":[{"url":"https://github.com/puma/puma/security/advisories/GHSA-2vqw-3mp8-cgmx","tags":["x_refsource_CONFIRM","advisory","web","report"]},{"url":"https://github.com/puma/puma/pull/3944","tags":["x_refsource_MISC","fix","web","report"]},{"url":"https://github.com/puma/puma/pull/3947","tags":["x_refsource_MISC","fix","web","report"]},{"url":"https://github.com/puma/puma/commit/439c6136d9c2275721b7864db3ee78af7c80889f","tags":["x_refsource_MISC","fix","web","report"]},{"url":"https://github.com/puma/puma/commit/ebe9db3929ab8299d19c8f5b41e8ef4f4b22fa58","tags":["x_refsource_MISC","fix","web","report"]},{"url":"https://github.com/puma/puma/releases/tag/v7.2.1","tags":["x_refsource_MISC","web","report"]},{"url":"https://github.com/puma/puma/releases/tag/v8.0.2","tags":["x_refsource_MISC","web","report"]},{"url":"https://github.com/rubysec/ruby-advisory-db/blob/master/gems/puma/CVE-2026-47737.yml","tags":["web"]},{"url":"https://www.cve.org/CVERecord/SearchResults?query=CVE-2026-47737","tags":["web"]},{"url":"https://nvd.nist.gov/vuln/detail/cve-2026-47737","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-2vqw-3mp8-cgmx"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47737.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-47737","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-47737","tags":["advisory"]},{"url":"https://github.com/puma/puma","tags":["package"]},{"url":"https://ubuntu.com/security/CVE-2026-47737","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-47737","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-47737","title":"Puma PROXY Protocol v1 Accepts Repeated Protocol Headers on Persistent Connections","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.","status":"published","published":"2026-07-14T19:45:16.648Z","modified":"2026-07-15T14:10:20.444Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high","assessor":"cna"}],"cwes":["CWE-290","CWE-345"],"updated_at":"2026-11-02T13:36:51.6229Z"}],"euvd":[{"id":"EUVD-2026-44427","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.","status":"published","published":"2026-07-14T19:45:16Z","modified":"2026-07-15T14:10:20Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high"}],"updated_at":"2026-11-02T18:19:53.226345Z"}],"ghsa":[{"id":"GHSA-2vqw-3mp8-cgmx","title":"Puma PROXY Protocol v1 Accepts Repeated Protocol Headers on Persistent Connections","description":"### Impact\n\nPuma is vulnerable to source IP spoofing when `set_remote_address proxy_protocol: :v1` is enabled and persistent connections are used.\n\nPROXY protocol v1 is a connection-level protocol. [Support was added to Puma in v5.5.0](https://github.com/puma/puma/issues/2651). A proxy sends one PROXY header at the beginning of a TCP connection, before any HTTP data. Puma incorrectly re-parsed PROXY protocol headers after each keep-alive request on the same connection. An attacker able to send HTTP requests through a trusted proxy could therefore inject a second PROXY header between HTTP requests. Puma would treat the injected header as authoritative for the next request and overwrite `REMOTE_ADDR`.\n\nThis can mislead applications or middleware that use `REMOTE_ADDR` for security decisions, rate limiting, auditing, or allow/deny lists.\n\n**Only deployments that explicitly enable PROXY protocol v1 are affected**, and will have set:\n\n```ruby\nset_remote_address proxy_protocol: :v1\n```\n\nPuma's default configuration is not affected. Deployments that do not use persistent connections to Puma are also not expected to be affected by this issue.\n\n### Patches\n\nUsers should upgrade to versions 7.2.1 or 8.0.2.\n\n### Workarounds\n\nDisable PROXY protocol v1 parsing if it is not required:\n\n ```ruby\n   # remove/comment this:\n   # set_remote_address proxy_protocol: :v1\n ```\n\nUsers can also disable persistent connections to Puma, for example:\n\n```ruby\nenable_keep_alives false\n```\n\n### References\n\n- [HAProxy PROXY protocol specification](https://www.haproxy.org/download/1.8/doc/proxy-protocol.txt)\n- [CVE-2025-31135 / GHSA-c2c3-pqw5-5p7c: go-guerrilla repeated PROXY command source IP spoofing](https://github.com/phires/go-guerrilla/security/advisories/GHSA-c2c3-pqw5-5p7c)\n- [Puma `set_remote_address` documentation](https://github.com/puma/puma/blob/master/lib/puma/dsl.rb)","status":"published","published":"2026-06-09T00:09:44Z","modified":"2026-11-02T22:08:42Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high"}],"cwes":["CWE-290","CWE-345"],"updated_at":"2026-11-03T00:02:45.112873Z"}],"nvd":[{"id":"CVE-2026-47737","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.","status":"published","published":"2026-07-14T20:17:03.767Z","modified":"2026-07-15T18:15:13.373Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high","assessor":"secondary"}],"cwes":["CWE-290","CWE-345"],"updated_at":"2026-11-02T14:12:29.879716Z"}],"osv":[{"id":"CVE-2026-47737","title":"Puma PROXY Protocol v1 Accepts Repeated Protocol Headers on Persistent Connections","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.","status":"published","published":"2026-07-14T19:45:16.648Z","modified":"2026-11-08T02:47:37.415280004Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high"}],"cwes":["CWE-290","CWE-345"],"updated_at":"2026-11-08T03:29:52.421856Z"},{"id":"DEBIAN-CVE-2026-47737","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.","status":"published","published":"2026-07-14T20:17:03.767Z","modified":"2026-10-07T12:00:07.664437867Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high"}],"updated_at":"2026-11-02T15:45:56.444225Z"},{"id":"GHSA-2vqw-3mp8-cgmx","title":"Puma PROXY Protocol v1 Accepts Repeated Protocol Headers on Persistent Connections","description":"### Impact\n\nPuma is vulnerable to source IP spoofing when `set_remote_address proxy_protocol: :v1` is enabled and persistent connections are used.\n\nPROXY protocol v1 is a connection-level protocol. [Support was added to Puma in v5.5.0](https://github.com/puma/puma/issues/2651). A proxy sends one PROXY header at the beginning of a TCP connection, before any HTTP data. Puma incorrectly re-parsed PROXY protocol headers after each keep-alive request on the same connection. An attacker able to send HTTP requests through a trusted proxy could therefore inject a second PROXY header between HTTP requests. Puma would treat the injected header as authoritative for the next request and overwrite `REMOTE_ADDR`.\n\nThis can mislead applications or middleware that use `REMOTE_ADDR` for security decisions, rate limiting, auditing, or allow/deny lists.\n\n**Only deployments that explicitly enable PROXY protocol v1 are affected**, and will have set:\n\n```ruby\nset_remote_address proxy_protocol: :v1\n```\n\nPuma's default configuration is not affected. Deployments that do not use persistent connections to Puma are also not expected to be affected by this issue.\n\n### Patches\n\nUsers should upgrade to versions 7.2.1 or 8.0.2.\n\n### Workarounds\n\nDisable PROXY protocol v1 parsing if it is not required:\n\n ```ruby\n   # remove/comment this:\n   # set_remote_address proxy_protocol: :v1\n ```\n\nUsers can also disable persistent connections to Puma, for example:\n\n```ruby\nenable_keep_alives false\n```\n\n### References\n\n- [HAProxy PROXY protocol specification](https://www.haproxy.org/download/1.8/doc/proxy-protocol.txt)\n- [CVE-2025-31135 / GHSA-c2c3-pqw5-5p7c: go-guerrilla repeated PROXY command source IP spoofing](https://github.com/phires/go-guerrilla/security/advisories/GHSA-c2c3-pqw5-5p7c)\n- [Puma `set_remote_address` documentation](https://github.com/puma/puma/blob/master/lib/puma/dsl.rb)","status":"published","published":"2026-06-09T00:09:44Z","modified":"2026-11-02T22:15:04.376466721Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high"}],"cwes":["CWE-290","CWE-345"],"updated_at":"2026-11-03T00:03:07.015763Z"},{"id":"UBUNTU-CVE-2026-47737","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.","status":"published","published":"2026-07-14T20:17:00Z","modified":"2026-10-17T13:00:20.462779701Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high"}],"updated_at":"2026-11-02T16:56:33.391918Z"}]}}