{"id":"UBUNTU-CVE-2026-47737","details":"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.","modified":"2026-07-15T19:48:19.641945162Z","published":"2026-07-14T20:17:00Z","upstream":["CVE-2026-47737"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-47737"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-47737"},{"type":"REPORT","url":"https://github.com/puma/puma/commit/439c6136d9c2275721b7864db3ee78af7c80889f"},{"type":"REPORT","url":"https://github.com/puma/puma/commit/ebe9db3929ab8299d19c8f5b41e8ef4f4b22fa58"},{"type":"REPORT","url":"https://github.com/puma/puma/pull/3944"},{"type":"REPORT","url":"https://github.com/puma/puma/pull/3947"},{"type":"REPORT","url":"https://github.com/puma/puma/releases/tag/v7.2.1"},{"type":"REPORT","url":"https://github.com/puma/puma/releases/tag/v8.0.2"},{"type":"REPORT","url":"https://github.com/puma/puma/security/advisories/GHSA-2vqw-3mp8-cgmx"}],"affected":[{"package":{"name":"puma","ecosystem":"Ubuntu:Pro:20.04:LTS","purl":"pkg:deb/ubuntu/puma?arch=source&distro=esm-apps%2Ffocal"},"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"],"ecosystem_specific":{"binaries":[{"binary_version":"3.12.4-1ubuntu2+esm2","binary_name":"puma"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-47737.json"}},{"package":{"name":"puma","ecosystem":"Ubuntu:Pro:22.04:LTS","purl":"pkg:deb/ubuntu/puma?arch=source&distro=esm-apps%2Fjammy"},"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"],"ecosystem_specific":{"binaries":[{"binary_name":"puma","binary_version":"5.5.2-2ubuntu2+esm2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-47737.json"}},{"package":{"name":"puma","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/puma?arch=source&distro=noble"},"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"],"ecosystem_specific":{"binaries":[{"binary_name":"puma","binary_version":"6.4.2-4ubuntu4.3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-47737.json"}},{"package":{"name":"puma","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/puma?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["6.6.0-4","6.6.0-4build1"],"ecosystem_specific":{"binaries":[{"binary_version":"6.6.0-4build1","binary_name":"puma"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-47737.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"},{"type":"Ubuntu","score":"medium"}]}