CVE-2026-25890

HIGH

filebrowser < 2.57.1 - Authenticated Authorization Bypass via Multiple Slash Path Manipulation

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 2 public exploits for CVE-2026-25890. PoCs published by XiaomingX, mbanyamer.

AI-analyzed exploit summary This repository contains a functional exploit for CVE-2026-25890, an access control bypass in FileBrowser ≤ v2.57.0. The exploit leverages multiple leading slashes to bypass `strings.HasPrefix()` checks in the authorization middleware, allowing low-privileged users to read, upload, or delete restricted files.

Description

File Browser provides a file managing interface within a specified directory and it can be used to upload, delete, preview, rename and edit files. Prior to 2.57.1, an authenticated user can bypass the application's "Disallow" file path rules by modifying the request URL. By adding multiple slashes (e.g., //private/) to the path, the authorization check fails to match the rule, while the underlying filesystem resolves the path correctly, granting unauthorized access to restricted files. This vulnerability is fixed in 2.57.1.

Exploits (2)

github WORKING POC 10 stars
by XiaomingX · pythonpoc
https://github.com/XiaomingX/data-cve-poc-py-v1/tree/main/2026/CVE-2026-25890

This repository contains a functional exploit for CVE-2026-25890, an access control bypass in FileBrowser ≤ v2.57.0. The exploit leverages multiple leading slashes to bypass `strings.HasPrefix()` checks in the authorization middleware, allowing low-privileged users to read, upload, or delete restricted files.

Classification
Working Poc 95%
Attack Type
Auth Bypass
Complexity
Trivial
Reliability
Reliable
Target: FileBrowser ≤ v2.57.0
Auth required
Prerequisites: valid low-privileged credentials · target path restricted from the user
devstral-2 · analyzed Feb 27, 2026 Full analysis →
nomisec WORKING POC
by mbanyamer · poc
https://github.com/mbanyamer/CVE-2026-25890-FileBrowser-Access-Control-Bypass

This repository contains a functional exploit for CVE-2026-25890, an access control bypass in FileBrowser ≤ v2.57.0. The exploit leverages multiple leading slashes to bypass `strings.HasPrefix()` checks while the filesystem still serves the canonical path.

Classification
Working Poc 95%
Attack Type
Auth Bypass
Complexity
Moderate
Reliability
Reliable
Target: FileBrowser ≤ v2.57.0
Auth required
Prerequisites: Valid low-privileged credentials · Access to the FileBrowser instance
devstral-2 · analyzed Feb 20, 2026 Full analysis →

Scores

CVSS v3 8.1
EPSS 0.0002
EPSS Percentile 3.9%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact total

Details

CWE
CWE-863 CWE-706
Status published
Products (2)
filebrowser/filebrowser < 2.57.1
filebrowser/filebrowser 0 - 2.57.1Go
Published Feb 09, 2026
Tracked Since Feb 18, 2026