High severity · published Sep 14, 2026
CVE-2026-90929
File Browser 2.5.0 Directory Deletion via Upload Failure Cleanup
8.1
CVSS
0.4%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 38% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FI
filebrowser · filebrowser
2.5.0 through 2.63.23 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-90929
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-90929
github.com
https://github.com/filebrowser/filebrowser/security/advisories/GHSA-c4fr-5f24-4wrj
www.vulncheck.com
https://www.vulncheck.com/advisories/file-browser-2.5.0-directory-deletion-via-upload-failure-cleanup
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