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SQL InjectionWeakness · CWE-89

CVE-2026-33734

MEDIUM · 6.9 CVSS v4.0 Published 2026-07-06
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
75/100
Remediation priority · High
Remotely reachable Zero-click 6 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. Versions 0.6.0 through 0.7.2 have a SQL injection vulnerability in the `Massmailer` module filter functionality. An authenticated administrator can supply crafted filter values when updating a mass email message, causing untrusted input to be interpolated directly into SQL in the recipient selection query. Version 0.8.0 patches the issue. Some workarounds are available. Restrict administrator access to trusted users only, disable the `Massmailer` module if it is not required, audit existing records in the `mod_massmailer` table for suspicious filter values, and/or review administrator activity related to `Massmailer` message updates.

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 0.6.0 through 0.7.2 contain a SQL injection vulnerability in the Massmailer module where authenticated administrator-supplied filter values are directly interpolated into SQL queries for recipient selection, allowing arbitrary SQL execution.

MitigationUpgrade to version 0.8.0 which patches the vulnerability, and implement workarounds including restricting admin access, disabling the Massmailer module if unused, and auditing existing records.

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
High
Authentication
X
User interaction
None
Scope
X

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/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 installed FOSSBilling version
    Locate the version file, typically at /includes/version.php or check the admin panel footer for the version number. The version may also be in a composer.json or package.json file in the web root.
    Affected if The installed version falls within the range 0.6.0 to 0.7.2 inclusive.
  2. Verify Massmailer module is installed
    Check if the Massmailer module directory exists, typically in /modules/Massmailer/ or /src/Modules/Massmailer/ within the FOSSBilling installation directory.
    Affected if The Massmailer module is present in the installation.
  3. Confirm admin panel accessibility
    Attempt to access the admin login page at /admin/index.php or /admin/ (adjust path if non-standard). Check whether the admin interface is reachable over the network.
    Affected if The admin panel is accessible without immediate authentication barriers blocking all access.
  4. Check for existing admin accounts
    Query the database users table (often named admin or user) or examine the admin user list through the admin panel if accessible. Look for accounts with admin-level privileges.
    Affected if At least one active administrator account exists in the system.
  5. Identify SQL query patterns in Massmailer code
    Examine the Massmailer module controller files, looking for direct SQL query construction without prepared statements. Search for patterns like $db->query() or direct string concatenation involving filter parameters.
    Affected if The code contains direct SQL interpolation of filter values without parameter binding.

The environment is affected if FOSSBilling version 0.6.0 through 0.7.2 is installed, the Massmailer module is present, and an authenticated administrator can access the admin panel to trigger the SQL injection via filter values.

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 version 0.8.0 which patches the vulnerability, and implement workarounds including restricting admin access, disabling the Massmailer module if unused, and auditing existing records.

Recommended fix High confidence

FOSSBilling version 0.8.0

  1. Backup the existing FOSSBilling database and files before upgrading
  2. Download FOSSBilling version 0.8.0 from the official GitHub repository (github.com)
  3. Replace the existing installation files with the 0.8.0 files, preserving any custom configuration
  4. Run any database migration scripts included in version 0.8.0
  5. Verify the Massmailer module is updated and the SQL injection vulnerability is patched
  6. Test the Massmailer filter functionality to ensure it works correctly
  7. Review administrator activity logs for any suspicious Massmailer message updates that may have occurred prior to the patch
Caveat Review the 0.8.0 release notes for any breaking changes or required configuration updates before upgrading

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

Have this fixed Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
13.0 hours of engineering $2,280
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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-2026-33734 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data