FOSSBilling: Mass assignment of group_id in guest client registration allows unauthorized promo code use

{
  "id": "e72e2995bc41ec8fbcf9361408a54e1737a110278554e5b132a6a2d6de99de83",
  "url": "https://osv.dev/vulnerability/CVE-2026-43925",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "FOSSBilling: Mass assignment of group_id in guest client registration allows unauthorized promo code use",
    "summary": "FOSSBilling is a free, open-source billing and client management system. Prior to version 0.8.0, an unauthenticated mass assignment vulnerability in the client self-registration endpoint allows any visitor to assign themselves to an arbitrary client group during sign-up. Because client groups can gate promo code eligibility, an attacker may apply group-restricted discount codes and receive unauthorized discounts. Version 0.8.0 contains a patch. As a workaround, administrators can either remove group restrictions from promo codes or disable client self-registration (Settings → Clients → Disable signup).",
    "evidence": "osv:CVE-2026-43925",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-43925",
      "aliases": [
        "CVE-2026-43925",
        "GHSA-q4rq-9844-r9w2"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/fossbilling/fossbilling",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "3bd35f5b2921d8a26a403142ae0408f95e6463cc"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.8.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.8.0"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "0.7.2",
            "0.7.1",
            "0.7.0",
            "0.6.22",
            "0.6.21",
            "0.6.20",
            "0.6.19",
            "0.6.18",
            "0.6.17",
            "0.6.16",
            "0.6.15",
            "0.6.14",
            "0.6.13",
            "0.6.12",
            "0.6.11",
            "0.6.10",
            "0.6.9",
            "0.6.8",
            "0.6.7",
            "0.6.6",
            "0.6.5",
            "0.6.4",
            "0.6.3",
            "0.6.2",
            "0.6.1",
            "0.6.0",
            "0.5.5",
            "0.5.4",
            "0.5.3",
            "0.5.2",
            "0.5.1",
            "0.5.0",
            "0.4.3",
            "0.4.2",
            "0.4.1",
            "0.4.0",
            "0.3.0",
            "0.2.10",
            "0.2.9",
            "0.2.8",
            "0.2.7",
            "0.2.6",
            "0.2.5",
            "0.2.4",
            "0.2.3",
            "0.2.2",
            "0.2.1",
            "0.2.0",
            "0.1.1",
            "0.1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-43925.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:35.745466799Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43925.json",
        "https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-q4rq-9844-r9w2",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-43925"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-915"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43925.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-43925",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 503081,
  "published_at": "2026-07-06T21:41:00.174+00:00"
}