CVE-2026-125109

{
  "id": "CVE-2026-125109",
  "sourceIdentifier": "[email protected]",
  "published": "2026-11-09T22:18:42.127",
  "lastModified": "2026-11-09T22:18:42.127",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Rack is a modular Ruby web server interface. From 3.0 until 3.1.23 and 3.2.8, Rack::Request#host_with_port, #base_url, and #url can return an attacker-controlled invalid authority from Host, X-Forwarded-Host, or Forwarded: host= verbatim. Applications without an independent host allowlist that use these methods for absolute URLs, redirects, or origin-dependent checks can emit attacker-chosen delimiters, enabling redirect manipulation, string-based allowlist bypass, or unescaped markup reflection. Rails overrides these methods and is not expected to be affected. This issue is fixed in versions 3.1.23 and 3.2.8."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "rack",
          "product": "rack",
          "versions": [
            {
              "version": ">= 3.0, < 3.1.23",
              "status": "affected"
            },
            {
              "version": ">= 3.2, < 3.2.8",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N",
          "baseScore": 4.8,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 2.5
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-1286"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/rack/rack/commit/4380381a56dc52556a436d6d794c8e18dc8b0565",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/rack/rack/commit/49386f460286b7346c7003b69a839de782cc8a39",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/rack/rack/releases/tag/v3.1.23",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/rack/rack/releases/tag/v3.2.8",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/rack/rack/security/advisories/GHSA-2j8w-xcrc-x985",
      "source": "[email protected]"
    }
  ]
}