CVE-2026-53647: FOSSBilling is a free, open-source billing and client
CVE-2026-53647 analysis covering impact, affected products, versions, remediation, and cross-checked defender guidance.
CVE-2026-53647 is a vulnerability published by NVD on 7/7/2026.
What happened
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.
Affected products and versions
- NVD has not published a normalized affected-product configuration yet.
Severity and weakness
CVSS: MEDIUM 6.9. Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X.
Weaknesses: CWE-200, CWE-306, CWE-862.
Known exploitation
No CISA KEV entry is currently attached to the NVD record.
What defenders should do
- Identify whether the affected product and version range exists in production.
- Review vendor advisories and release notes before change windows.
- Patch, upgrade, disable the vulnerable component, or apply vendor mitigations.
- Verify the running version after deployment, not only the package inventory.
Official and supporting references
- No vendor advisory tagged by NVD at draft time.