CVE-2026-53647 FOSSBilling vulnerable to unauthenticated API key configuration disclosure via guest Serviceapikey get_info endpoint
Unauthenticated access to the guest API endpoint allows retrieving sensitive custom configuration data from API keys, exposing business-sensitive information.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-53647?
CVE-2026-53647 is a medium-severity vulnerability in FOSSBilling, published on 6 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
FOSSBilling is a free, open-source billing and client management system. In versions 0.5.3 through 0.7.2, the Guest `serviceapikey/get_info` API endpoint is accessible without authentication. Any caller with a valid API key can retrieve all custom configuration parameters (`custom_*` fields) stored in the key's database record. These custom fields are populated by billing administrators and can contain business-sensitive data such as pricing tiers, feature flags, rate limits, expiry overrides, or access scope data. Version 0.8.0 patches the issue. Some workarounds are available. Administrators can avoid storing sensitive data in `custom_*` API key configuration fields, monitor API logs for suspicious calls to `/api/guest/serviceapikey/get_info`, and/or disable the Serviceapikey module if not in active use.
Which versions are affected by CVE-2026-53647?
How do I fix CVE-2026-53647?
No fix has been published for CVE-2026-53647 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-53647 being exploited?
There is no known exploitation of CVE-2026-53647 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as GHSA-737q-9gpr-6mpq.