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Fencer Vulns
medium 6.9

CVE-2026-53647 json

FOSSBilling vulnerable to unauthenticated API key configuration disclosure via guest Serviceapikey get_info endpoint

published 2026-07-06 4 mo ago modified 2026-07-07 4 mo ago also EUVD-2026-41973

cvss
6.9
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 45%
public exploits
0
none known

Summary

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.

Patch / fix

  • fossbilling fossbilling 0.8.0

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
4 mo ago

Exploit prediction

0.54% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 6.9 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
CNA 4.0 6.9 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

Affected products

  • FOSSBilling FOSSBilling

Classification

Weakness
  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
  • CWE-306 Missing Authentication for Critical Functionality
  • CWE-862 Missing Authorization

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.