CVE-2026-43921

Published Jul 6, 2026 CWE-94

Description

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.

Weakness Type (CWE)

CWE-94 CWE-94

References

Frequently Asked Questions

What is CVE-2026-43921? +
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.
How do I check if I'm vulnerable to CVE-2026-43921? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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