CVE-2026-53645

high

Description

FOSSBilling is a free, open-source billing and client management system. Versions prior to 0.8.0 allow a low-privileged staff account to grant arbitrary module permissions to itself through the admin API, resulting in persistent privilege escalation. A staff user that only has `staff.create_and_edit_staff` can call `/api/admin/staff/permissions_update` targeting their own account and write any permission structure, bypassing the intended role-based access control boundary. Version 0.8.0 patches the issue. Some workarounds are available. Restrict the `staff.create_and_edit_staff` permission to only highly trusted staff members and/or use a reverse proxy or WAF to restrict access to `/api/admin/staff/permissions_update` to specific trusted roles.

References

https://github.com/FOSSBilling/FOSSBilling/security/advisories/GHSA-4hf7-xxxw-64rm

Details

Source: Mitre, NVD

Published: 2026-07-06

Updated: 2026-07-06

Risk Information

CVSS v2

Base Score: 6.5

Vector: CVSS2#AV:N/AC:L/Au:S/C:P/I:P/A:P

Severity: Medium

CVSS v3

Base Score: 8.8

Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Severity: High

CVSS v4

Base Score: 8.5

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:H/SI:H/SA:L