bbs-go through 4.4.6 Incorrect Authorization via /api/admin/user/synccount

{
  "id": "7f97da64e169492b25ab4a217ec125d7cc938846c0bd0b5f90aefc0e319cc14a",
  "url": "https://osv.dev/vulnerability/CVE-2026-103396",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "bbs-go through 4.4.6 Incorrect Authorization via /api/admin/user/synccount",
    "summary": "bbs-go through 4.4.6 contains a permission bypass vulnerability in the AdminMiddleware authorization logic where the read-only dashboard.user.view permission rule matches the /api/admin/user/synccount endpoint before the intended dashboard.user.update rule. Authenticated users with only view permissions can call the synccount endpoint to trigger expensive full-table user recounts and cache invalidations, causing denial of service through repeated concurrent database operations.",
    "evidence": "osv:CVE-2026-103396",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-103396",
      "aliases": [
        "CVE-2026-103396"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/mlogclub/bbs-go",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "97d0bb3dcbacd686fd5300295afbf4f4a5da7609"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "4.4.6"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "fixed": "97d0bb3dcbacd686fd5300295afbf4f4a5da7609"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v4.4.6",
            "v4.4.5",
            "v4.4.5-rc2",
            "v4.4.5-rc1",
            "v4.4.4",
            "v4.4.3",
            "v4.4.3-rc3",
            "v4.4.3-rc2",
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            "v4.4.2-rc4",
            "v4.4.2-rc3",
            "v4.4.2-rc2",
            "v4.4.2-rc1",
            "v4.4.1-rc4",
            "v4.4.1",
            "v4.4.1-rc3",
            "v4.4.1-rc2",
            "v4.4.1-rc1",
            "v4.4.0-rc5",
            "v4.4.0",
            "v4.4.0-rc4",
            "v4.3.9",
            "v4.3.6",
            "v4.3.5",
            "v4.3.4",
            "v4.3.3",
            "v4.3.2",
            "v4.3.1",
            "v4.3.0",
            "v4.1.2",
            "v4.1.1",
            "v4.1.0",
            "v4.0.6",
            "v4.0.5",
            "v4.0.3",
            "v4.0.1",
            "v4.0.0",
            "v4.0.0-beta2",
            "v4.0.0-beta1",
            "v3.5.6",
            "v3.5.5",
            "v3.5.4",
            "3.5.4",
            "v3.5.3",
            "v3.5.2",
            "v3.5.1",
            "v3.5.0",
            "v3.4.3",
            "v3.4.2",
            "v3.4.1",
            "v3.4.0",
            "v3.3.2",
            "3.3.2",
            "v3.3.1",
            "v3.3.0",
            "v3.2.6",
            "v3.2.5",
            "v3.2.4",
            "v3.2.3",
            "v3.2.2",
            "v3.2.1",
            "v3.2.0",
            "v3.1.9",
            "v3.1.8",
            "v3.1.7",
            "v3.1.6",
            "v3.1.5",
            "v3.1.4",
            "v3.1.3",
            "v3.1.2",
            "v3.1.1",
            "v3.1.0",
            "v3.0.9",
            "v3.0.7",
            "v3.0.6",
            "v3.0.5",
            "v3.0.4",
            "v3.0.3",
            "v3.0.2",
            "v3.0.1",
            "v3.0.0",
            "v2.0.0",
            "v1.0.5",
            "v1.0.4",
            "v1.0.3",
            "v1.0.2",
            "v1.0.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-103396.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:48.561275897Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/103xxx/CVE-2026-103396.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-103396",
        "https://www.vulncheck.com/advisories/bbs-go-through-4.4.6-incorrect-authorization-via-api-admin-user-synccount",
        "https://github.com/mlogclub/bbs-go/issues/303",
        "https://github.com/mlogclub/bbs-go/commit/97d0bb3dcbacd686fd5300295afbf4f4a5da7609",
        "https://github.com/mlogclub/bbs-go",
        "https://github.com/mlogclub/bbs-go/blob/v4.4.6/internal/handlers/admin/user_handlers.go#L47-L59",
        "https://github.com/mlogclub/bbs-go/blob/v4.4.6/internal/permissions/admin_permission_registry.go#L59-L60"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-863"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/103xxx/CVE-2026-103396.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-103396",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 516928,
  "published_at": "2026-09-30T14:48:56.405+00:00"
}