CVE-2026-33734
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.
- ⚠ NVD has not scored this CVE yet - manual triage required (common for recent CVEs)
Severity & exploitation scoring
AV:_/AC:_/... vector string published by NVD.ATT&CK techniques
1Techniques this CVE enables. Pills with a solid outline are high confidence - named directly in ATT&CK or Nuclei, or human-curated by CTID; the rest are inferred from the weakness type using MITRE's CVE Mapping Methodology and the CWE → CAPEC chain. Broad, generic-weakness guesses are filtered out. A small N× marks a technique that N independent sources agree on.
▤ Build a SIEM detection for these techniquesCAPEC attack patterns
6Attack patterns this CVE enables - the bridge from weakness to ATT&CK technique.