CVE-2026-104109 in FileRise
Summary
by MITRE • 10/14/2026
FileRise is a self-hosted web-based file manager with multi-file upload, editing, and batch operations. Prior to 3.23.0, FileRise validates archive entry names but extracts them directly into the authorized live destination before validating resolved paths. If that destination already contains a symlink to a directory outside the storage root, an authenticated non-administrator with extract permission who can upload or otherwise place an attacker-controlled ZIP in that folder can place an ordinary archive entry beneath the link. ZipArchive::extractTo() can then overwrite an external file, and post-extraction cleanup can delete that target through the same linked parent, only where the FileRise process has the required filesystem write or removal permission. The advisory does not establish that the attacker can create the prerequisite symlink through FileRise. This issue is fixed in version 3.23.0.
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Analysis
by VulDB Data Team • 10/14/2026
FileRise is a self-hosted web-based file management solution designed to facilitate multi-file uploads, editing, and batch operations for users managing digital assets on their own infrastructure. The software provides functionality for handling various archive formats, allowing authenticated users to extract contents from compressed files into designated storage directories. This capability is essential for efficient data organization but introduces significant security considerations regarding how the application handles file paths during extraction processes.
A critical path traversal vulnerability exists in versions of FileRise prior to 3.23.0 due to a flawed validation sequence within the archive extraction logic. The core technical flaw lies in the order of operations performed by the underlying PHP ZipArchive::extractTo() function when integrated into the application's workflow. Specifically, the software validates the names of entries contained within an uploaded ZIP file but proceeds to extract these entries directly into the authorized live destination directory before validating whether the resolved absolute paths remain within the intended storage root boundaries. This temporal gap between validation and execution creates a window for exploitation where maliciously crafted archive contents can bypass security checks if they interact with existing filesystem structures in unexpected ways.
The exploitability of this vulnerability relies on specific environmental conditions involving symbolic links, commonly referred to as symlinks. If an attacker or another user has previously created a symlink within the authorized storage directory that points to a location outside the designated file root, such as a system configuration directory or sensitive data folder, the validation logic fails to detect the path escape during extraction. When an authenticated non-administrator with extract permissions uploads and triggers the processing of an archive containing entries designed to traverse through this symlinked parent directory, the ZipArchive::extractTo() function will write files into the external target location rather than within the sandboxed storage area. This effectively allows the attacker to overwrite arbitrary files on the server that are writable by the FileRise process user account.
The operational impact of this vulnerability extends beyond simple file overwriting. Following the extraction, FileRise performs cleanup operations which may involve deleting temporary or processed archive contents. If these cleanup routines interact with the same linked parent directory structure, they can inadvertently delete files located in the external target path through the symlinked route. This capability transforms a potential data integrity issue into a severe denial of service condition or complete loss of critical system files, depending on which external directories are targeted and what permissions the FileRise process holds regarding removal operations. The severity is compounded by the fact that authentication is required, but only non-administrator privileges are needed to trigger this behavior if the prerequisite symlink exists.
It is important to note a limitation in the current understanding of the attack surface: the advisory does not confirm whether an attacker can create the necessary symbolic link within FileRise itself. This implies that the vulnerability likely requires either pre-existing symlinks created by administrators or other users with sufficient filesystem permissions, or it relies on external factors such as misconfigured hosting environments where symlink creation is possible through alternative means. Therefore, while the extraction flaw is severe, its practical exploitation depends heavily on the specific deployment configuration and existing file system state of the target environment.
To mitigate this vulnerability, organizations running FileRise must upgrade to version 3.23.0 or later immediately, as this release corrects the validation sequence to ensure path resolution occurs before extraction begins. In environments where upgrading is not immediately feasible, administrators should audit storage directories for any symbolic links pointing outside the designated file root and remove them if they are unnecessary. Additionally, applying strict filesystem permissions so that the FileRise process user has minimal write access limited strictly to its own data directory can reduce the impact of potential path traversal attempts. Regular security audits focusing on input validation order in archive handling libraries are recommended to prevent similar issues across other web applications utilizing PHP's ZipArchive functionality.
This vulnerability aligns with CWE-22, which describes Improper Limitation of a Pathname to a Restricted Directory, commonly known as directory traversal. The exploitation technique also relates to ATT&CK T1564.008, Hidden Files and Directories: Symbolic Link, where attackers leverage symbolic links to bypass access controls or manipulate file system operations. By understanding these classifications, security teams can better contextualize the risk within broader threat landscapes and implement more robust defense-in-depth strategies that include both application-level fixes and infrastructure-level hardening measures.