CVE-2026-53648
FOSSBilling is a free, open-source billing and client management system. Prior to version 0.8.1, downloadable product files are stored using a deterministic filename-derived path. When an administrator uploads a file for a downloadable product, FOSSBilling stores the file as md5(<original filename>) under the uploads directory.
Because the stored path depends only on the client-supplied filename, two different downloadable products, or product/order files, uploaded with the same original filename will resolve to the same stored file path. A later upload can overwrite an earlier upload, causing customers or administrators downloading the earlier product to receive the later file instead. Version 0.8.1 patches the issue.
Some workarounds are available. Restrict the servicedownloadable.manage permission to fully trusted administrators only. As an operational mitigation, ensure downloadable product files use unique filenames before upload.
This reduces accidental collisions but does not fully address the underlying issue.
- ⚠ NVD has not scored this CVE yet - manual triage required (common for recent CVEs)
Exploitation momentum
2 days of EPSSSeverity & exploitation scoring
AV:_/AC:_/... vector string published by NVD.ATT&CK techniques
4Techniques 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.
CAPEC attack patterns
8Attack patterns this CVE enables - the bridge from weakness to ATT&CK technique.