Home/CVE/FOSSBilling is a free, open-source billing and client management system. Prior to version 0.8.1, downloadable product fi
CVE

CVE-2026-53648

FOSSBilling is a free, open-source billing and client management system. Prior to version 0.8.1, downloadable product fi

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.

EPSS 0.00264
EPSS exploitation odds0.26% · top 82%
Monitor
  • ⚠ NVD has not scored this CVE yet - manual triage required (common for recent CVEs)
Look this up elsewhere - one-click external pivots
How to read a CVE - triage first, then detect and patch
This page is every public fact about CVE-2026-53648, cross-linked. Its job is to answer one question fast - does this need my attention now? - and then hand you the two things you do about it. Here is how an analyst reads it.
Triage: should I act now? Four signals, and they are not interchangeable:
CVSSseverity - how bad it is IF exploited, 0-10. A high CVSS alone is not urgency; a flaw can be a perfect 10 and never actually be attacked. EPSSprobability - a model’s estimate of the chance it is exploited in the next 30 days, 0-1. This is the “will it actually happen” signal. CISA KEVconfirmed - it is being exploited in the wild right now. The strongest signal on the page; KEV beats any score. Weaponisedavailability - public exploits / PoCs, and especially Metasploit modules rated Excellent / Great. Reliable, packaged exploit code means low-skill attackers can use it today.
How they combine: KEV, or a dependable Metasploit module, means patch now regardless of CVSS. High CVSS + low EPSS + no exploit is real but not an emergency - schedule it. Low CVSS but KEV-listed still gets patched now. The verdict above already weighed these for you; this is how it got there.
Then what - two workflows:
Detectwhen you cannot patch today, follow this CVE to the ATT&CK techniques it enables, then Build a SIEM detection (the green button) - author a rule, test it in Atomic, deploy it. That buys visibility while the patch waits. PatchAffected products / packages tell you if you are exposed; Fixed versions by distribution and Vendor advisories give the exact version that closes it.
Reading order for the panels below: verdict + badges, then Public exploits / Metasploit (is it weaponised), then ATT&CK techniques + Sigma / IDS rules (can I detect it), then Affected products / packages + Fixed versions (am I exposed, what patches it), then Threat actors / IOCs (who uses it), then Scoring & timeline / references (the evidence).

Exploitation momentum

2 days of EPSS
stable
Exploitation pressure is steady. This reads the direction and speed of EPSS over time, which can move before EPSS itself peaks or before CISA lists it.
Window

Severity & exploitation scoring

EPSS exploitation probability
0.26%
Top 82%odds of exploitation in the next 30 days
CVSS metric silhouette
No structured CVSS vector for this CVE. Older entries often have only a numeric base score - the metric breakdown radar requires a full AV:_/AC:_/... vector string published by NVD.
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
no
Tech impact
partial

ATT&CK techniques

4

Techniques 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 marks a technique that N independent sources agree on.

▤ Build a SIEM detection for these techniques
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References & Sources

1
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.