dbcve.org
Improper Access ControlWeakness · CWE-284

CVE-2026-27708

HIGH · 7.1 CVSS v4.0 Published 2026-06-24
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
77/100
Remediation priority · High
Remotely reachable Zero-click 8 weeks old

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 · unedited
FOSSBilling is a free, open-source billing and client management system. In versions 0.7.2 and prior, the Servicecustom Client API's __call method accepts an order_id parameter and fetches the associated order without verifying the authenticated client owns it, potentially exposing cross-client data through IDOR. An authenticated client can access any other client's custom service by guessing sequential order IDs. This can lead to a confidentiality breach — attackers can read client PII (name, email, phone, address, company details, VAT number) and service configuration data belonging to other clients. This issue has been fixed in version 0.8.0.

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 confidence

FOSSBilling versions 0.7.2 and prior contain an IDOR vulnerability in the Servicecustom Client API's __call method. The method accepts an order_id parameter but fails to verify that the authenticated client owns the referenced order, allowing any authenticated client to access arbitrary client data by iterating through sequential order IDs.

MitigationUpgrade to FOSSBilling version 0.8.0 or later, which implements proper ownership validation. After upgrading, verify the fix by testing that clients cannot access other clients' orders via the API.

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:H/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

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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify FOSSBilling version
    Locate the version file (typically includes/version.php or check admin panel About page) and compare to 0.7.2
    Affected if Installed version is 0.7.2 or lower
  2. Verify Servicecustom module is enabled
    Check the modules list in FOSSBilling admin panel or inspect the modules/Servicecustom directory exists and is active in the database
    Affected if Servicecustom module is installed and active
  3. Confirm API access is enabled for clients
    Inspect API configuration settings in admin panel or config file to verify client API access is permitted
    Affected if Client API access is enabled (authenticated clients can make API calls)
  4. Test order ownership validation
    Using an authenticated client API session, attempt to access an order by ID using the Servicecustom __call method and verify whether the system returns data for orders not owned by that client
    Affected if API returns data for order IDs that do not belong to the authenticated client (indicating missing ownership validation)

User is affected if FOSSBilling version is 0.7.2 or lower, the Servicecustom module is enabled, client API access is permitted, and the API returns data for orders not owned by the requesting client.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to FOSSBilling version 0.8.0 or later, which implements proper ownership validation. After upgrading, verify the fix by testing that clients cannot access other clients' orders via the API.

Recommended fix High confidence

0.8.0

  1. Backup the existing FOSSBilling installation and database before proceeding with any changes
  2. Download FOSSBilling version 0.8.0 from the official repository (github.com/FOSSBilling/FOSSBilling)
  3. Replace the existing installation files with the new version 0.8.0 files
  4. Run any database migrations if required by the upgrade process
  5. Verify the upgrade was successful by checking the FOSSBilling admin panel version indicator
  6. Test that authenticated clients can no longer access other clients' orders via the Servicecustom API by attempting to access order IDs belonging to different clients
  7. Confirm that client PII is now properly restricted to the owning client only
Caveat Review the FOSSBilling 0.8.0 release notes for any breaking changes or backward incompatibilities before upgrading in production

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
9.0 hours of engineering $1,570
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-27708 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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