# CVE-2026-72837: File Browser before 2.63.20 Privilege Escalation via Proxy Authentication

> Attackers with valid upstream credentials can access other users' files due to improper isolation in proxy authentication paths.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/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 Aug 2026
- **Updated:** 14 Aug 2026
- **Also known as:** GHSA-6x93-4cv7-m749, GHSA-j7jh-37pf-mf8h

## What is CVE-2026-72837?

CVE-2026-72837 is a high-severity vulnerability in filebrowser, published on 14 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

File Browser versions before 2.63.20 fail to honor the createUserDir isolation in proxy and hook authentication auto-provisioning paths. Attackers with valid upstream-authenticated credentials can read, modify, delete, and share files belonging to other users by exploiting the server root scope assignment.

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2026-72837?


## How do I fix CVE-2026-72837?

No fix has been published for CVE-2026-72837 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-72837 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-72837 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72837 and fix it if it is affected.

What it is: CVE-2026-72837 is a high-severity vulnerability in filebrowser, published on 14 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-72837 exists.

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-2026-72837/ (Markdown: https://insights.sbomify.com/CVE-2026-72837/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72837
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72837
- OSV: https://osv.dev/vulnerability/CVE-2026-72837

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72837/
Summaries are generated and may contain mistakes; the official description above is the record.