# CVE-2026-90929: File Browser 2.5.0 Directory Deletion via Upload Failure Cleanup

> Authenticated users with Create and Modify permissions can delete unauthorized directories via a flawed upload cleanup mechanism in File Browser.

- **Severity:** High 7.2 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Sep 2026
- **Updated:** 14 Sep 2026
- **Also known as:** GHSA-78rx-w3p8-c3v7, GHSA-c4fr-5f24-4wrj

## What is CVE-2026-90929?

CVE-2026-90929 is a high-severity missing authorization vulnerability in filebrowser, published on 14 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

File Browser versions >= 2.5.0 and <= 2.63.23 contain an incorrect authorization flaw in the direct-upload endpoint (resourcePostHandler in http/resource.go). Unlike the TUS upload handler, the direct-upload handler does not reject a target that is an existing directory; a POST with ?override=true aimed at a directory fails inside writeFile (a directory cannot be opened for writing) and the failure-cleanup path then calls Fs.RemoveAll on the request path, recursively deleting the entire tree. This cleanup is gated by neither the Perm.Delete permission nor the checkDescendants rule walk applied by the delete and patch handlers, so an authenticated non-administrator holding only the default Create and Modify permissions can delete directories they are not authorized to delete, including rule-denied files within them. Deletion remains confined to the user's scope because ScopedFs.RemoveAll still enforces the scope guard. The faulty cleanup was introduced in v2.5.0; no patched version is available.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2026-90929?


## How do I fix CVE-2026-90929?

No fix has been published for CVE-2026-90929 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-90929 being exploited?

There is no known exploitation of CVE-2026-90929 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90929 and fix it if it is affected.

What it is: CVE-2026-90929 is a high-severity missing authorization vulnerability in filebrowser, published on 14 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-90929 in the wild and no public exploit code.

Affected product: filebrowser. 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-2026-90929/ (Markdown: https://insights.sbomify.com/CVE-2026-90929/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90929
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90929
- OSV: https://osv.dev/vulnerability/CVE-2026-90929

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90929/
Summaries are generated and may contain mistakes; the official description above is the record.