CVE-2026-54089

File Browser: Authentication Bypass via Proxy Auth Header Forgery

Published Jun 25, 2026 CVSS 3.1 · 9.1 Critical EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-xqp3-jq6g-x3qm File Browser: Authentication Bypass via Proxy Auth Header Forgery
History
Type Values Removed Values Added
First Time appeared Filebrowser
Filebrowser filebrowser
Vendors & Products Filebrowser
Filebrowser filebrowser
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title File Browser: Authentication Bypass via Proxy Auth Header Forgery
Weaknesses CWE-287
CWE-290
References
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Jun 25, 2026, 6:33 PM
Reserved
Jun 11, 2026, 6:44 PM
Status
Deferred
Published
Jun 25, 2026, 7:16 PM
Modified
Jun 25, 2026, 7:58 PM