# CVE-2026-53648: FOSSBilling: Downloadable product files can be overwritten through filename collisions

> Attackers can overwrite downloadable product files by uploading files with identical names, causing customers to receive incorrect content.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:L/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-x7p2-xhvc-cfp9

## What is CVE-2026-53648?

CVE-2026-53648 is a medium-severity 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. 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.

Weakness: CWE-73 (External Control of File Name or Path), CWE-668 (Exposure of Resource to Wrong Sphere)

## Which versions are affected by CVE-2026-53648?


## How do I fix CVE-2026-53648?

No fix has been published for CVE-2026-53648 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-53648 being exploited?

There is no known exploitation of CVE-2026-53648 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-53648 and fix it if it is affected.

What it is: CVE-2026-53648 is a medium-severity vulnerability in FOSSBilling, published on 6 Jul 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-53648 in the wild and no public exploit code.

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-2026-53648/ (Markdown: https://insights.sbomify.com/CVE-2026-53648/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53648
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53648
- OSV: https://osv.dev/vulnerability/CVE-2026-53648

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53648/
Summaries are generated and may contain mistakes; the official description above is the record.