Atom table exhaustion via unrecognized URL schemes in hackney

{
  "id": "e63eb5e4d5d3addc8b84046b545855835dd492895b42610bc99857d4b128d077",
  "url": "https://osv.dev/vulnerability/CVE-2026-47067",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Atom table exhaustion via unrecognized URL schemes in hackney",
    "summary": "Allocation of Resources Without Limits or Throttling vulnerability in benoitc hackney allows Flooding. The URL parser in src/hackney_url.erl converts every unrecognized URL scheme to a permanent BEAM atom via binary_to_atom/2. BEAM atoms are never garbage-collected and the atom table defaults to a hard limit of 1,048,576 entries. An attacker who can supply URLs with attacker-chosen scheme prefixes — directly as request targets, as configured webhook URLs, or via Location headers followed during redirects — can exhaust the atom table and crash the entire BEAM VM with system_limit. This issue affects hackney: from 2.0.0 before 4.0.1.",
    "evidence": "osv:CVE-2026-47067",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-47067",
      "aliases": [
        "CVE-2026-47067",
        "EEF-CVE-2026-47067",
        "GHSA-9653-rcfr-5c62"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/benoitc/hackney",
              "type": "GIT",
              "events": [
                {
                  "introduced": "a7ce34b42892ab305b2ef7dbe873bcabf4ef93ca"
                },
                {
                  "fixed": "c41c8d48ace8141b003f6f1de3ca6734a0c53056"
                },
                {
                  "fixed": "31f6f0e27e096ad88743dfded4f030a3ee74972e"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:benoitc:hackney:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "2.0.0"
                      },
                      {
                        "fixed": "4.0.1"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "31f6f0e27e096ad88743dfded4f030a3ee74972e"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "4.0.0",
            "3.2.1",
            "3.2.0",
            "3.1.2",
            "3.1.1",
            "3.1.0",
            "3.0.3",
            "3.0.2",
            "3.0.1",
            "2.0.1",
            "2.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-47067.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:32.965199139Z",
      "provider": "osv",
      "references": [
        "https://cna.erlef.org/cves/CVE-2026-47067.html",
        "https://github.com",
        "https://osv.dev/vulnerability/EEF-CVE-2026-47067",
        "https://repo.hex.pm",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47067.json",
        "https://github.com/benoitc/hackney/security/advisories/GHSA-9653-rcfr-5c62",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-47067",
        "https://github.com/benoitc/hackney/commit/31f6f0e27e096ad88743dfded4f030a3ee74972e",
        "https://github.com/benoitc/hackney"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-770"
        ],
        "cna_assigner": "EEF",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47067.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-47067",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 499899,
  "published_at": "2026-05-25T14:00:48.507+00:00"
}