Auth bypass in Fossbilling

CVE-2026-53647

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.

Vulnerability class: Information Disclosure

Published · last modified .

EPSS exploit prediction

EPSS: 0.005 (43.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 44th percentile — 43.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-53647: held from 0.005 to 0.005.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2026-53647?
CVE-2026-53647 is a vulnerability in Fossbilling, classified under Information Disclosure. Published 2026-07-07.
Is CVE-2026-53647 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.