{
  "affected": [
    {
      "database_specific": {
        "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-2vqw-3mp8-cgmx/GHSA-2vqw-3mp8-cgmx.json"
      },
      "package": {
        "ecosystem": "RubyGems",
        "name": "puma",
        "purl": "pkg:gem/puma"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "8.0.0"
            },
            {
              "fixed": "8.0.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "8.0.0",
        "8.0.1"
      ]
    },
    {
      "database_specific": {
        "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/06/GHSA-2vqw-3mp8-cgmx/GHSA-2vqw-3mp8-cgmx.json"
      },
      "package": {
        "ecosystem": "RubyGems",
        "name": "puma",
        "purl": "pkg:gem/puma"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.5.0"
            },
            {
              "fixed": "7.2.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "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"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-47737"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-290",
      "CWE-345"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-06-09T00:09:44Z",
    "nvd_published_at": "2026-07-14T20:17:03Z",
    "severity": "HIGH"
  },
  "details": "### 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)",
  "id": "GHSA-2vqw-3mp8-cgmx",
  "modified": "2026-11-02T22:15:04.376466721Z",
  "published": "2026-06-09T00:09:44Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/puma/puma/security/advisories/GHSA-2vqw-3mp8-cgmx"
    },
    {
      "type": "WEB",
      "url": "https://github.com/puma/puma/pull/3944"
    },
    {
      "type": "WEB",
      "url": "https://github.com/puma/puma/pull/3947"
    },
    {
      "type": "WEB",
      "url": "https://github.com/puma/puma/commit/439c6136d9c2275721b7864db3ee78af7c80889f"
    },
    {
      "type": "WEB",
      "url": "https://github.com/puma/puma/commit/ebe9db3929ab8299d19c8f5b41e8ef4f4b22fa58"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/puma/puma"
    },
    {
      "type": "WEB",
      "url": "https://github.com/puma/puma/releases/tag/v7.2.1"
    },
    {
      "type": "WEB",
      "url": "https://github.com/puma/puma/releases/tag/v8.0.2"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/puma/CVE-2026-47737.yml"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/cve-2026-47737"
    },
    {
      "type": "WEB",
      "url": "https://www.cve.org/CVERecord/SearchResults?query=CVE-2026-47737"
    }
  ],
  "schema_version": "1.9.2",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Puma PROXY Protocol v1 Accepts Repeated Protocol Headers on Persistent Connections"
}