Most recent entries from all

EUVD-2026-330377

2026-10-08T00:22:52.688457+00:00

EUVD-2026-330377

fkie_cve-2026-54089

2026-10-08T00:22:52.688554+00:00

File Browser is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory. Starting with 2.0.0-rc.1, when FileBrowser is configured with proxy authentication (auth.method=proxy), any unauthenticated attacker who can reach the server directly can impersonate any user - including admin - by sending a single forged HTTP header. No credentials are required. Additionally, specifying a non-existent username causes the server to automatically create a new user account, providing an account creation primitive with no authorization. This is an already known issue that has been documented in the documentation for several years, but has not been documented as a vulnerability before.

GHSA-xqp3-jq6g-x3qm — File Browser: Authentication Bypass via Proxy Auth Header Forgery

2026-10-08T00:22:52.688611+00:00

Affected: Go: github.com/filebrowser/filebrowser/v2

## Summary

When FileBrowser is configured with proxy authentication (`auth.method=proxy`), any unauthenticated attacker who can reach the server directly can impersonate **any user - including admin** - by sending a single forged HTTP header. No credentials are required. Additionally, specifying a non-existent username causes the server to **automatically create a new user account**, providing an account creation primitive with no authorization.

**This is an already known issue that has been documented in the documentation for several years, but has not been documented as a vulnerability before.**

## Severity

**HIGH** - CVSS 3.1: **8.1** (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N)

## Affected Component

- **File:** [`auth/proxy.go`](https://github.com/filebrowser/filebrowser/blob/main/auth/proxy.go), lines 21-28 - **CWE:** [CWE-287](https://cwe.mitre.org/data/definitions/287.html) (Improper Authentication), [CWE-290](https://cwe.mitre.org/data/definitions/290.html) (Authentication Bypass by Spoofing) - **Affected versions:** All versions supporting `auth.method=proxy`

## Prerequisite: Proxy Auth Must Be Enabled

This vulnerability is **NOT exploitable on default configuration** (`auth.method=json`). It requires the administrator to have configured proxy authentication mode. However, this is a **common production deployment pattern** - many organizations run FileBrowser behind a reverse proxy that handles SSO/LDAP/OAuth authentication:

- **nginx** + Authelia / Authentik - **…