CVE-2026-53645
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedFOSSBilling 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceFOSSBilling versions prior to 0.8.0 contain an IDOR (Insecure Direct Object Reference) combined with insufficient authorization check allowing a low-privileged staff user with only `staff.create_and_edit_staff` permission to call the `/api/admin/staff/permissions_update` API endpoint on their own account and inject arbitrary permission structures, effectively escalating their privileges beyond the intended role-based access control boundaries.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- Authentication
- X
- User interaction
- None
- Scope
- X
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/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
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify installed FOSSBilling versionLocate the version file or configuration. Check for a version.php, composer.json, or config.php file in the FOSSBilling installation directory that contains the version number.Affected if The installed version is any release prior to 0.8.0 (e.g., 0.7.x, 0.6.x, etc.)
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Verify the vulnerable API endpoint existsInspect the FOSSBilling source code for the presence of the /api/admin/staff/permissions_update endpoint. Look in the API controller or route definition files.Affected if The endpoint /api/admin/staff/permissions_update exists in the codebase and is accessible without additional authorization checks beyond the staff.create_and_edit_staff permission.
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Confirm staff.create_and_edit_staff permission is assignableReview the permission configuration or database to verify that the staff.create_and_edit_staff permission can be granted to staff users. Check the permissions system to see if this permission controls access to the permissions_update endpoint.Affected if The staff.create_and_edit_staff permission exists and can be granted to staff users, granting them access to the vulnerable endpoint.
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Audit staff user permission assignmentsQuery the staff user database or admin interface to list all staff accounts and their current permission sets. Compare each user's assigned permissions against their role-based access control boundaries.Affected if Any staff user possesses module permissions that exceed what their assigned role should grant, indicating successful exploitation of the IDOR vulnerability.
A user is affected if they run FOSSBilling version below 0.8.0 and have staff accounts with the staff.create_and_edit_staff permission, as the vulnerable endpoint allows permission escalation beyond role boundaries.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade to FOSSBilling version 0.8.0 or later. As immediate workarounds, restrict the `staff.create_and_edit_staff` permission to highly trusted staff members only and/or deploy a reverse proxy or WAF rule to limit access to `/api/admin/staff/permissions_update` endpoint.
FOSSBilling 0.8.0
- 1. Create a complete backup of the FOSSBilling installation directory and database before upgrading.
- 2. Download FOSSBilling version 0.8.0 from the official GitHub repository (github.com/fossbilling/fossbilling) or official distribution channel.
- 3. Replace all existing FOSSBilling files with the version 0.8.0 files, preserving any custom configuration files if required.
- 4. Run any database migrations if provided with the 0.8.0 release.
- 5. Verify the upgrade by logging into the admin panel and confirming the version displays as 0.8.0.
- 6. Test that a staff user with only `staff.create_and_edit_staff` permission can no longer escalate their own privileges via the `/api/admin/staff/permissions_update` API endpoint.
- 7. As an additional mitigation, restrict the `staff.create_and_edit_staff` permission to only highly trusted staff members, and consider configuring a reverse proxy or WAF to restrict access to the `/api/admin/staff/permissions_update` endpoint.
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation6.0 h
- Testing5.0 h
- Review / QA3.0 h
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Free · runs locallyCheck whether your project pulls in CVE-2026-53645 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-53645 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
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- Version or environment caveats, and links to real fixes
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