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, the TUS resumable upload handler parses the Upload-Length header as a signed 64-bit integer without validating that the value is non-negative, allowing an authenticated user to supply a negative value that instantly satisfies the upload completion condition upon the first PATCH request. This causes the server to fire after_upload exec hooks with empty or partial files, enabling an attacker to repeatedly trigger any configured hook with arbitrary filenames and zero bytes written. The impact ranges from DoS through expensive processing hooks, to command injection amplification when combined with malicious filenames, to abuse of upload-driven workflows like S3 ingestion or database inserts. Even without exec hooks enabled, the negative Upload-Length creates inconsistent cache entries where files are marked complete but contain no data. All deployments using the TUS upload endpoint (/api/tus) are affected, with the enableExec flag escalating the impact from cache inconsistency to remote command execution. At the time of publication, no patch or mitigation was available to address this issue.

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-ffx7-75gc-jg7c File Browser TUS Negative Upload-Length Fires Post-Upload Hooks Prematurely
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 20 Mar 2026 09:00:00 +0000

Type Values Removed Values Added
First Time appeared Filebrowser
Filebrowser filebrowser
Vendors & Products Filebrowser
Filebrowser filebrowser

Fri, 20 Mar 2026 00:00:00 +0000

Type Values Removed Values Added
Description 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, the TUS resumable upload handler parses the Upload-Length header as a signed 64-bit integer without validating that the value is non-negative, allowing an authenticated user to supply a negative value that instantly satisfies the upload completion condition upon the first PATCH request. This causes the server to fire after_upload exec hooks with empty or partial files, enabling an attacker to repeatedly trigger any configured hook with arbitrary filenames and zero bytes written. The impact ranges from DoS through expensive processing hooks, to command injection amplification when combined with malicious filenames, to abuse of upload-driven workflows like S3 ingestion or database inserts. Even without exec hooks enabled, the negative Upload-Length creates inconsistent cache entries where files are marked complete but contain no data. All deployments using the TUS upload endpoint (/api/tus) are affected, with the enableExec flag escalating the impact from cache inconsistency to remote command execution. At the time of publication, no patch or mitigation was available to address this issue.
Title File Browser TUS Negative Upload-Length Fires Post-Upload Hooks Prematurely
Weaknesses CWE-190
References
Metrics cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:L/SA:L'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-03-19T23:31:51.340Z

Reserved: 2026-03-13T18:53:03.532Z

Link: CVE-2026-32759

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-03-20T00:16:17.270

Modified: 2026-03-20T00:16:17.270

Link: CVE-2026-32759

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-03-20T08:54:16Z

Weaknesses