CVE-2026-90929

File Browser 2.5.0 Directory Deletion via Upload Failure Cleanup

Published Sep 14, 2026 CVSS 4.0 · 7.2 High EPSS < 1% KEV · Not listed
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.

Analysis

AI-generated

Technical impact

The vulnerability arises from an inadequate authorization check in File Browser’s direct‑upload endpoint. When a user issues a POST request to a directory with the query parameter ?override=true, the upload fails inside writeFile because a directory cannot be opened for writing. The subsequent failure‑cleanup routine incorrectly calls Fs.RemoveAll on the requested path, which recursively deletes the entire directory tree. Because this cleanup path bypasses both the Delete permission check and the rule‑denied hierarchy walk normally applied to deletion operations, an authenticated non‑administrator holding only Create and Modify permissions can delete directories they are not authorized to delete, including files that the access rules forbid. The flaw is categorized as an insufficient authorization error (CWE‑863).

Affected Systems

File Browser versions from 2.5.0 through 2.63.23 are affected. The CNA identifies the product as filebrowser:filebrowser, and the generic CPE cpe:2.3:a:filebrowser:filebrowser:*:*:*:*:*:*:* includes all releases in that range. No patched version is currently available, so vulnerable installations remain susceptible.

Risk and Exploitability

The CVSS score of 7.2 indicates a moderate‑to‑high severity. No EPSS score is provided, and the vulnerability is not listed in the CISA KEV catalog, so there is no evidence yet of widespread exploitation. An attacker must possess a valid authenticated session for a non‑administrator user with Create and Modify permissions; beyond the user’s scoped directories the vulnerability does not permit broader deletion. Nonetheless, deleting entire directory trees within a user's scope can cause serious data multi‑tenant deployments.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Remove the Modify permission for users who do not require directory deletion capabilities, limiting them to Create and Modify without Delete.
  • Disable or filter the override=true query parameter on the direct‑upload endpoint by configuring the application or placing a reverse proxy rule to block such requests.
  • Enable detailed audit logging for upload and delete activities and regularly review logs for unexpected directory deletions.

Generated by OpenCVE AI on September 15, 2026 at 14:13 UTC.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title File Browser 2.5.0 Directory Deletion via Upload Failure Cleanup
First Time appeared Filebrowser
Filebrowser filebrowser
Weaknesses CWE-863
CPEs cpe:2.3:a:filebrowser:filebrowser:*:*:*:*:*:*:*:*
Vendors & Products Filebrowser
Filebrowser filebrowser
References
Metrics cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H'}

cvssV4_0

{'score': 7.2, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Sep 14, 2026, 6:12 PM
Reserved
Sep 14, 2026, 11:33 AM
Status
Awaiting Analysis
Published
Sep 14, 2026, 1:19 PM
Modified
Sep 24, 2026, 8:44 PM