# CVE-2026-33734: FOSSBilling has improper SQL neutralization in `Massmailer` recipient filters

> An authenticated administrator can exploit SQL injection in FOSSBilling's Massmailer module to manipulate recipient selection queries, potentially exposing or altering data.

- **Severity:** Medium 6.9 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 6 Jul 2026
- **Updated:** 7 Jul 2026
- **Also known as:** GHSA-jf7m-j359-2899

## What is CVE-2026-33734?

CVE-2026-33734 is a medium-severity SQL injection vulnerability in FOSSBilling, published on 6 Jul 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

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.

Weakness: CWE-89 (Improper Neutralization of Special Elements used in an SQL Command)

## Which versions are affected by CVE-2026-33734?


## How do I fix CVE-2026-33734?

No fix has been published for CVE-2026-33734 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-33734 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33734 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33734 and fix it if it is affected.

What it is: CVE-2026-33734 is a medium-severity SQL injection vulnerability in FOSSBilling, published on 6 Jul 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33734 exists.

Affected product: FOSSBilling. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-33734/ (Markdown: https://insights.sbomify.com/CVE-2026-33734/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33734
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33734
- OSV: https://osv.dev/vulnerability/CVE-2026-33734

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33734/
Summaries are generated and may contain mistakes; the official description above is the record.