Quick answer
Direct answer
Risk scores
| CVSS metric | What it means |
|---|---|
| Attack vector (AV:N) | Network: reachable remotely |
| Attack complexity (AC:L) | Low complexity |
| Attack requirements (AT:P) | Attack requirements present |
| Privileges required (PR:N) | No privileges required |
| User interaction (UI:N) | No user interaction |
| Confidentiality (VC:H) | High confidentiality impact |
| Integrity (VI:N) | No integrity impact |
| Availability (VA:N) | No availability impact |
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
About Filebrowser
CVE-2026-35604 affects Filebrowser, a product from Filebrowser. Before acting, confirm where Filebrowser runs in your estate, who owns it and whether it is reachable from the internet, because exposure decides real risk more than the score alone.
What the flaw is
In plain terms: File Browser is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory. Prior to 2.63.1, when an admin revokes a user's Share and Download permissions, existing share links created by that user remain fully accessible to unauthenticated users. The public share download handler does not re-check the share owner's current permissions. This vulnerability is fixed in 2.63.1.
The weakness class is Incorrect Authorization. The permission check exists but gets the answer wrong.
Based on its CVSS vector, the flaw can be reached over the network, needs no login, and needs no user interaction. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Affected versions and timeline
| Field | Detail |
|---|---|
| Product | Filebrowser |
| Affected versions | Filebrowser before 2.63.1 |
| Published | Apr 7, 2026 |
| Last modified | Jun 17, 2026 |
| Added to CISA KEV | Not listed |
| Assigning CNA | security-advisories@github.com |
How to detect it
- Inventory every instance of Filebrowser and record the running version against the affected range above.
- Check external attack surface scans for internet facing instances of the component.
- Review logs on affected systems for unusual requests, errors or new processes around the vulnerable function.
- Confirm with an authenticated vulnerability scan once your scanner has a check for this CVE.
How to fix it
- Apply the fixed version of Filebrowser named in the vendor advisory.
- If patching must wait, restrict network access to the affected service and put it behind authentication or a web application firewall rule.
- Rescan after the change to prove the exposure is gone, then close the ticket.
CTEM action plan
| CTEM stage | What to do for this CVE |
|---|---|
| Scope | Add every business service that depends on Filebrowser to the current CTEM cycle. |
| Discover | Find all instances, including shadow and cloud deployments, and record versions and exposure. |
| Prioritize | Rank using EPSS and CVSS together with asset exposure and business impact. |
| Validate | Confirm the flaw is reachable and exploitable in your environment and that compensating controls work. |
| Mobilize | Assign the fix to the asset owner with a due date matched to the priority, then verify closure. |
CWE References
- CWE-863: Incorrect Authorization More CVEs with this weakness
Technical References
Frequently asked questions
Related CVEs
File Browser is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory. Prior to 2.63.1, the fix in commit b6a4fb1 ("self-registered users don't get execute perms") stripped Execute permission and Commands from users created via the signup handler. The same fix was not applied to the proxy auth handler. Users auto-created on first successful proxy-auth login are granted execution capabilities from global defaults, even though the signup path was explicitly changed to prevent execution rights from being inherited by automatically provisioned accounts. This vulnerability is fixed in 2.63.1.
File Browser is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory. From 2.0.0 until 2.33.8, the hook system in File Browser — which executes administrator-defined shell commands on file events such as upload, rename, and delete — is vulnerable to OS command injection. Variable substitution for values like $FILE and $USERNAME is performed via os.Expand without sanitization. An attacker with file write permission can craft a malicious filename containing shell metacharacters, causing the server to execute arbitrary OS commands when the hook fires. This results in Remote Code Execution (RCE). This feature has been disabled by default for all installations from v2.33.8 onwards, including for existent installations.
File Browser is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory. Prior to version 2.62.2, the EPUB preview function in File Browser is vulnerable to Stored Cross-Site Scripting (XSS). JavaScript embedded in a crafted EPUB file executes in the victim's browser when they preview the file. This issue has been patched in version 2.62.2.
File Browser is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory. Prior to version 2.62.2, the signupHandler in File Browser applies default user permissions via d.settings.Defaults.Apply(user), then strips only Admin. The Execute permission and Commands list from the default user template are not stripped. When an administrator has enabled signup, server-side execution, and set Execute=true in the default user template, any unauthenticated user who self-registers inherits shell execution capabilities and can run arbitrary commands on the server. This issue has been patched in version 2.62.2.
File Browser is a file managing interface for uploading, deleting, previewing, renaming, and editing files within a specified directory. In versions 2.61.2 and below, any unauthenticated visitor can register a full administrator account when self-registration (signup = true) is enabled and the default user permissions have perm.admin = true. The signup handler blindly applies all default settings (including Perm.Admin) to the new user without any server-side guard that strips admin from self-registered accounts. The signupHandler is supposed to create unprivileged accounts for new visitors. It contains no explicit user.Perm.Admin = false reset after applying defaults. If an administrator (intentionally or accidentally) configures defaults.perm.admin = true and also enables signup, every account created via the public registration endpoint is an administrator with full control over all files, users, and server settings. This issue has been resolved in version 2.62.0.
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 version 2.61.1, a broken access control vulnerability in the TUS protocol DELETE endpoint allows authenticated users with only Create permission to delete arbitrary files and directories within their scope, bypassing the intended Delete permission restriction. Any multi-user deployment where administrators explicitly restrict file deletion for certain users is affected. This issue has been patched in version 2.61.1.
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