CVE-2026-75602
Received Received - Intake

Path Traversal in OpenList File List Program

Publication date: 2026-09-03

Last updated on: 2026-09-03

Assigner: GitHub, Inc.

Description
OpenList a file list program that supports multiple storage. Prior to 4.2.3, OpenList's offline-download feature at POST /api/fs/add_offline_download with tool: "SimpleHttp" accepts an attacker-supplied URL and saves its bytes under a per-task temporary directory before transferring them to the user's destination storage. The temporary filename comes from the attacker-controlled Content-Disposition header, is passed from parseFilenameFromContentDisposition in internal/offline_download/http/util.go to filepath.Join(task.TempDir, filename) in SimpleHttp.Run in internal/offline_download/http/client.go, and is opened with os.Create without a containment check. Because filepath.Join cleans .. segments, a non-admin user with PermAddOfflineDownload on any path can traverse out of task.TempDir and create, truncate, or overwrite any file writable by the OpenList process whose parent directory already exists. The server/handles/offline_download.go AddOfflineDownload route uses normal user authentication rather than AuthAdmin, and local-storage destinations fall through tryPutUrl in internal/offline_download/tool/add.go to the vulnerable SimpleHttp.Run path. This issue is fixed in version 4.2.3.

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Meta Information

Published
2026-09-03
Last Modified
2026-09-03
Generated
2026-09-03
AI Q&A
2026-09-03
EPSS Evaluated
N/A
NVD
CVE-2026-75602
EUVD
EUVD-2026-70550

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
openlistteam openlist to 4.2.3 (exc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-73 The product allows user input to control or influence paths or file names that are used in filesystem operations.
CWE-22 The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

Attack-Flow Graph

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Executive Summary

CVE-2026-75602 is a path traversal vulnerability in OpenList's SimpleHttp offline-download feature. It allows authenticated users with PermAddOfflineDownload to write arbitrary files outside intended directories by exploiting the Content-Disposition header. The application fetches a file from an attacker-controlled URL, extracts the filename from the header, and writes it to a temporary directory without proper validation. Due to Go's filepath.Join behavior, path traversal sequences like ../../ are resolved, enabling file writes anywhere the OpenList process has permissions.

The vulnerability exists because the filename from the Content-Disposition header is used verbatim without sanitization, and no containment checks are performed after joining the path. This affects versions up to 4.2.2 and was patched in 4.2.3.

Detection Guidance

To detect this vulnerability, check OpenList versions before 4.2.3. Inspect network traffic for POST requests to /api/fs/add_offline_download with tool: SimpleHttp. Look for unusual file writes or path traversal patterns in logs. Verify if users with PermAddOfflineDownload can create or modify files outside intended directories.

Impact Analysis

This vulnerability can lead to severe impacts such as overwriting configuration files (enabling admin takeover), dropping webshells, or replacing the application binary. Attackers can create, truncate, or overwrite any file writable by the OpenList process if the parent directory already exists. The attack requires only a valid user account with PermAddOfflineDownload permission, not administrative privileges.

Compliance Impact

This vulnerability could lead to unauthorized file writes, potentially exposing or altering sensitive data. For GDPR, it may result in unauthorized access to personal data, violating confidentiality and integrity requirements. For HIPAA, it could compromise protected health information integrity or availability if configuration files or data are overwritten.

Mitigation Strategies

Upgrade OpenList to version 4.2.3 or later immediately. Remove or restrict PermAddOfflineDownload permissions for non-admin users. Implement strict input validation for Content-Disposition headers. Monitor file system changes for unauthorized writes.

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