CVE-2026-27611
Insecure Direct Object Reference in FileBrowser Quantum Allows Unauthorized Download
Publication date: 2026-02-25
Last updated on: 2026-02-27
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| gtsteffaniak | filebrowser_quantum | to 1.1.3 (exc) |
| gtsteffaniak | filebrowser_quantum | From 1.2.0 (inc) to 1.2.6 (exc) |
| gtsteffaniak | filebrowser_quantum | 1.1.3 |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-287 | When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. |
| CWE-200 | The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. |
| CWE-288 | The product requires authentication, but the product has an alternate path or channel that does not require authentication. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability affects FileBrowser Quantum versions prior to 1.1.3-stable and 1.2.6-beta. When users share files protected by a password, the API returns a direct download link within the share details. This direct download link can be accessed by anyone who has the share link, without needing to enter the password.
The issue occurs because the API endpoint `/public/api/shareinfo?hash=<share_hash>` returns detailed share information including a `downloadURL` field that contains a direct download link with an embedded token. This tokenized URL allows unauthorized users to bypass the password protection and download the file directly.
How can this vulnerability impact me? :
This vulnerability can lead to unauthorized access to files that were intended to be protected by a password. Anyone with the share link can bypass the password prompt and download the shared file directly.
As a result, sensitive or confidential information could be exposed to unintended recipients, potentially leading to data leaks or breaches.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
[{'type': 'paragraph', 'content': 'This vulnerability can be detected by checking if the API endpoint `/public/api/shareinfo?hash=<share_hash>` returns a JSON response containing a `downloadURL` field that allows direct file download without requiring a password.'}, {'type': 'paragraph', 'content': 'A suggested command to detect this on your system or network is to perform a GET request to the share info API endpoint with a known share hash and inspect the response for the presence of the direct download URL.'}, {'type': 'list_item', 'content': 'curl -s "https://example.com/public/api/shareinfo?hash=<share_hash>" | grep downloadURL'}, {'type': 'paragraph', 'content': 'If the `downloadURL` is present and accessible without authentication, it indicates the vulnerability is present.'}] [2]
What immediate steps should I take to mitigate this vulnerability?
The immediate mitigation step is to upgrade FileBrowser Quantum to version 1.1.3-stable or 1.2.6-beta or later, where this vulnerability has been fixed.
Until the upgrade can be applied, avoid sharing files with password protection using the vulnerable versions, or disable anonymous access on password-protected shares to prevent unauthorized direct downloads.