Filebrowser File Browser up to 2.63.23 Direct-Upload Endpoint http/resource.go WriteFile privileges management

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Filebrowser File Browser up to 2.63.23. This affects the function WriteFile of the file http/resource.go of the component Direct-Upload Endpoint. This manipulation causes privileges management. This vulnerability is tracked as CVE-2026-90929. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability has been found in Filebrowser File Browser up to 2.63.23 and classified as problematic. Affected by this vulnerability is the function WriteFile of the file http/resource.go of the component Direct-Upload Endpoint. The manipulation with an unknown input leads to a privileges management vulnerability. The CWE definition for the vulnerability is CWE-269. The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor. As an impact it is known to affect integrity, and availability. The summary by CVE is:

File Browser versions >= 2.5.0 and <= 2.63.23 contain an incorrect authorization flaw in the direct-upload endpoint (resourcePostHandler in http/resource.go). Unlike the TUS upload handler, the direct-upload handler does not reject a target that is an existing directory; a POST with ?override=true aimed at a directory fails inside writeFile (a directory cannot be opened for writing) and the failure-cleanup path then calls Fs.RemoveAll on the request path, recursively deleting the entire tree. This cleanup is gated by neither the Perm.Delete permission nor the checkDescendants rule walk applied by the delete and patch handlers, so an authenticated non-administrator holding only the default Create and Modify permissions can delete directories they are not authorized to delete, including rule-denied files within them. Deletion remains confined to the user's scope because ScopedFs.RemoveAll still enforces the scope guard. The faulty cleanup was introduced in v2.5.0; no patched version is available.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-90929 since 09/14/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/14/2026). MITRE ATT&CK project uses the attack technique T1068 for this issue.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

• Filebrowser

Name

• File Browser

Version

• 2.63.0
• 2.63.1
• 2.63.2
• 2.63.3
• 2.63.4
• 2.63.5
• 2.63.6
• 2.63.7
• 2.63.8
• 2.63.9
• 2.63.10
• 2.63.11
• 2.63.12
• 2.63.13
• 2.63.14
• 2.63.15
• 2.63.16
• 2.63.17
• 2.63.18
• 2.63.19
• 2.63.20
• 2.63.21
• 2.63.22
• 2.63.23

CPE 2.3info

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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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