RabbitMQ: Plaintext username:password stored in an insecure cookie after successful POST /login

{
  "id": "6fdb3f5aa566a80d82a52d6b74e2bbcf88ebde0b17c808d193fd3de1eabf7b02",
  "url": "https://osv.dev/vulnerability/BIT-rabbitmq-2026-67236",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "RabbitMQ: Plaintext username:password stored in an insecure cookie after successful POST /login",
    "summary": "RabbitMQ is a messaging and streaming broker. From 4.2.0 until 4.2.8 and 4.3.2, a successful POST /login caused is_authorized/2 to set an auth cookie containing base64-encoded username:password credentials without HttpOnly, Secure, SameSite, or expiration protections. Because base64 is encoding rather than encryption, an attacker with same-origin cross-site scripting, an HTTP-readable network position, or local access to the browser cookie store could recover the actual login credentials; older browsers that treated an absent SameSite attribute as None also sent the cookie cross-site. This issue is fixed in versions 4.2.8 and 4.3.2.",
    "evidence": "osv:BIT-rabbitmq-2026-67236",
    "products": [
      {
        "name": {
          "value": "rabbitmq",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "4.2.8",
            "evidence": "/affected/0/ranges"
          },
          {
            "value": "4.3.2",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "BIT-rabbitmq-2026-67236",
      "aliases": [
        "BIT-rabbitmq-2026-67236",
        "CVE-2026-67236",
        "GHSA-88vh-gx85-p36m"
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "4.2.0"
                },
                {
                  "fixed": "4.2.8"
                },
                {
                  "introduced": "4.3.0"
                },
                {
                  "fixed": "4.3.2"
                }
              ]
            }
          ],
          "package": {
            "name": "rabbitmq",
            "purl": "pkg:bitnami/rabbitmq",
            "ecosystem": "Bitnami"
          },
          "severity": [
            {
              "type": "CVSS_V4",
              "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
            }
          ],
          "database_specific": {
            "source": "https://github.com/bitnami/vulndb/tree/main/data/rabbitmq/BIT-rabbitmq-2026-67236.json"
          }
        }
      ],
      "modified": "2026-10-16T09:45:12.659147849Z",
      "provider": "osv",
      "references": [
        "https://github.com/rabbitmq/rabbitmq-server/commit/df9e7f4c0afd311a672705f020d301efad355745",
        "https://github.com/rabbitmq/rabbitmq-server/commit/edf1fbc7217aaf736955d2e13c9534901a2e0778",
        "https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.2.8",
        "https://github.com/rabbitmq/rabbitmq-server/releases/tag/v4.3.2",
        "https://github.com/rabbitmq/rabbitmq-server/security/advisories/GHSA-88vh-gx85-p36m",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-67236"
      ],
      "provider_metadata": {
        "cpes": [
          "cpe:2.3:a:vmware:rabbitmq:*:*:*:*:*:*:*:*"
        ],
        "severity": "High"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-67236",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/database_specific/severity"
  },
  "source_id": "core-osv",
  "document_id": 338210,
  "published_at": "2026-10-01T09:33:31.47+00:00"
}