RabbitMQ: list_to_atom on auth_mechanism URI tokens in amqp_client

{
  "id": "c0eeb9e571be9f94cdbebfb79af2bec22300c4b44249d3d90d9be79c98d7a894",
  "url": "https://osv.dev/vulnerability/CVE-2026-67222",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "RabbitMQ: list_to_atom on auth_mechanism URI tokens in amqp_client",
    "summary": "RabbitMQ is a messaging and streaming broker. From 3.13.0 until 3.13.15, 4.0.20, 4.1.11, and 4.2.6, mechanisms/1 applied list_to_atom/1 to every colon-delimited token in an attacker-controlled auth_mechanism value, permanently consuming Erlang VM atoms and allowing the node to be crashed with a large request. Exploitation requires the Shovel or Federation plugin to be in use, and setting auth_mechanism requires the policymaker tag. This issue is fixed in versions 3.13.15, 4.0.20, 4.1.11, and 4.2.6.",
    "evidence": "osv:CVE-2026-67222",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-67222",
      "aliases": [
        "BIT-rabbitmq-2026-67222",
        "CVE-2026-67222",
        "GHSA-85jr-6rr2-j73r"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/rabbitmq/rabbitmq-server",
              "type": "GIT",
              "events": [
                {
                  "introduced": "95c501fbad76c66156346cf364d158d6e30aa4d9"
                },
                {
                  "fixed": "8a56c37f099a7bf609a555de3f0ff8ed23964d20"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "4.2.0"
                      },
                      {
                        "fixed": "4.2.6"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "8a56c37f099a7bf609a555de3f0ff8ed23964d20"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v4.2.6"
                  },
                  {
                    "cpe": "cpe:2.3:a:broadcom:rabbitmq_server:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "4.2.0"
                      },
                      {
                        "fixed": "4.2.6"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v4.2.5",
            "v4.2.4",
            "v4.2.3",
            "v4.2.2",
            "v4.2.1",
            "v4.2.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-67222.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:26.700292958Z",
      "provider": "osv",
      "references": [
        "https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.6",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/67xxx/CVE-2026-67222.json",
        "https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-85jr-6rr2-j73r",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-67222"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-400"
        ],
        "cna_assigner": "GitHub_M",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "3.13.0"
                  },
                  {
                    "fixed": "3.13.15"
                  },
                  {
                    "introduced": "4.0.0"
                  },
                  {
                    "fixed": "4.0.20"
                  },
                  {
                    "introduced": "4.1.0"
                  },
                  {
                    "fixed": "4.1.11"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StringRangeExpression"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/67xxx/CVE-2026-67222.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-67222",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 493402,
  "published_at": "2026-09-25T16:00:16.437+00:00"
}