{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:benoitc:hackney:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "0.13.0"
              },
              {
                "fixed": "4.0.1"
              }
            ],
            "source": [
              "CPE_RANGE",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "fd2158b39b0aa139bb90f0c867f246ddfec072e6"
            },
            {
              "fixed": "c41c8d48ace8141b003f6f1de3ca6734a0c53056"
            },
            {
              "fixed": "452620a92ec1da2e6b4862a049a2a4f04b42068f"
            }
          ],
          "repo": "https://github.com/benoitc/hackney",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-pj7v-xfvx-wmjq"
  ],
  "database_specific": {
    "cna_assigner": "EEF",
    "cwe_ids": [
      "CWE-436",
      "CWE-918"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47076.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "introduced": "4d725507588942fd00efca15b86da3273656510a"
          },
          {
            "fixed": "452620a92ec1da2e6b4862a049a2a4f04b42068f"
          }
        ],
        "source": "AFFECTED_FIELD"
      }
    ]
  },
  "details": "Interpretation Conflict vulnerability in benoitc hackney allows Server Side Request Forgery. hackney_url:normalize/2 URL-decodes the host component after the URL has been parsed into a #hackney_url{} record. OTP's uri_string:parse/1 and inet:parse_address/1 do not decode percent-escapes in the host, so a URL such as http://%31%32%37%2E%30%2E%30%2E%31/ is seen by a caller's allowlist validator with host %31%32%37%2E%30%2E%30%2E%31 (not an IP address), which passes the allowlist check. hackney's normalizer then decodes the host to 127.0.0.1 and opens a TCP connection to loopback. Because hackney:request/5 always calls hackney_url:normalize/2 with no opt-out, every request that takes a binary or list URL is affected. The same technique reaches cloud instance metadata services (169.254.169.254), RFC1918 networks, and any admin interface listening on localhost.\n\nThis issue affects hackney: from 0.13.0 before 4.0.1.",
  "id": "CVE-2026-47076",
  "modified": "2026-07-08T05:36:12.432859168Z",
  "published": "2026-05-25T14:00:46.707Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://cna.erlef.org/cves/CVE-2026-47076.html"
    },
    {
      "type": "WEB",
      "url": "https://github.com"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-47076"
    },
    {
      "type": "WEB",
      "url": "https://repo.hex.pm"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47076.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/benoitc/hackney/security/advisories/GHSA-pj7v-xfvx-wmjq"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-47076"
    },
    {
      "type": "FIX",
      "url": "https://github.com/benoitc/hackney/commit/452620a92ec1da2e6b4862a049a2a4f04b42068f"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/benoitc/hackney"
    }
  ],
  "schema_version": "1.7.5",
  "severity": [
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "SSRF allowlist bypass via percent-encoded host in hackney"
}