{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0.6.10"
              },
              {
                "fixed": "0.8.0"
              },
              {
                "fixed": "0.7.2"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "DESCRIPTION"
            ]
          },
          "events": [
            {
              "introduced": "153be25dd938dd951655a9bf596ac83159594e0f"
            },
            {
              "fixed": "3bd35f5b2921d8a26a403142ae0408f95e6463cc"
            }
          ],
          "repo": "https://github.com/fossbilling/fossbilling",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-v4j9-w6pj-38w5"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-94"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43921.json"
  },
  "details": "FOSSBilling is a free, open-source billing and client management system. Versions 0.6.10 through 0.7.2 have a PHP code injection vulnerability in FOSSBilling's `Config::prettyPrintArrayToPHP()` method. When configuration values are updated, string values are written into `config.php` without escaping single quotes. Because `config.php` is loaded via a bare `include` on every HTTP request, an attacker with admin privileges can inject arbitrary PHP code that executes on every subsequent request. Version 0.8.0 contains a patch. Some workarounds are available. Restrict admin access to trusted personnel only; audit `config.php` for unexpected PHP code; and/ or at the reverse proxy/WAF level, restrict access to admin API endpoints that modify configuration.",
  "id": "CVE-2026-43921",
  "modified": "2026-07-09T03:51:53.546657162Z",
  "published": "2026-07-06T21:38:49.078Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43921.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-v4j9-w6pj-38w5"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43921"
    }
  ],
  "schema_version": "1.7.5",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H",
      "type": "CVSS_V4"
    }
  ],
  "summary": "FOSSBilling vulnerable to arbitrary PHP code injection via unescaped config serialization"
}