CVE-2026-91934 in Flowise
Summary
by MITRE • 09/15/2026
Flowise versions before 3.1.4 fail to validate file paths in the SQL Database Chain node when connecting to SQLite databases, allowing authenticated attackers to write arbitrary files. Attackers can write malicious SQLite databases to system directories or inject files into the web root to execute commands or perform stored XSS attacks.
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Analysis
by VulDB Data Team • 09/15/2026
The vulnerability identified in Flowise versions prior to 3.1.4 represents a critical security flaw within the SQL Database Chain node, specifically when interacting with SQLite database backends. This issue stems from an insufficient validation of file paths provided by authenticated users during configuration or execution phases. In typical software architecture, input sanitization is paramount to prevent attackers from manipulating underlying system resources. However, in this specific implementation, the application fails to properly restrict or validate the directory paths and filenames associated with SQLite database connections. This lack of rigorous path traversal checks allows an attacker who has valid authentication credentials to specify arbitrary file locations on the host operating system rather than being confined to a designated data directory.
The technical mechanism behind this flaw involves the direct use of user-supplied input for constructing file paths without adequate normalization or restriction against directory traversal sequences such as dot-dot-slash characters. When an authenticated attacker provides a maliciously crafted path, the application interprets it literally and attempts to open or create a database connection at that specified location. Because SQLite databases are essentially single files on disk, this capability effectively grants the attacker write access to any file system location where the Flowise process has permissions. This transforms what should be an isolated data storage operation into a potential arbitrary file write vulnerability, bypassing standard sandboxing expectations for application-level database interactions.
The operational impact of this vulnerability is severe and multifaceted, primarily due to the privileged nature often associated with web application processes. An attacker can exploit this flaw to overwrite critical system files if the service runs with elevated privileges, potentially leading to full system compromise through privilege escalation techniques. More commonly in typical deployment scenarios, attackers target directories accessible by the web server or the Flowise process itself. By writing a malicious SQLite database file into the web root directory, an attacker can leverage the application's own functionality against it. Since many frameworks and tools may attempt to parse or display content from these files under certain conditions, this enables Stored Cross-Site Scripting attacks where injected JavaScript payloads are served to unsuspecting users visiting specific endpoints.
Furthermore, if the environment allows for command execution via SQLite extensions or similar mechanisms, writing a malicious database file could facilitate remote code execution. This is particularly dangerous in containerized environments or serverless deployments where lateral movement might be limited but initial access is highly valuable. The ability to write arbitrary files also facilitates persistence, as attackers can place backdoors or configuration tampering scripts that survive application restarts. This vulnerability fundamentally undermines the integrity and confidentiality guarantees expected from an authenticated session within the Flowise platform, turning a data management tool into a vector for system-wide compromise.
To mitigate this risk, organizations running affected versions of Flowise must immediately upgrade to version 3.1.4 or later, where these path validation checks have been implemented by the developers. Until upgrading is possible, administrators should enforce strict network segmentation and least-privilege principles, ensuring that the user account executing the Flowise process has minimal file system permissions, restricted specifically to a dedicated data directory with no write access elsewhere on the host system. Additionally, implementing Web Application Firewall rules can help detect and block requests containing suspicious path traversal patterns or unusual database connection strings before they reach the application logic.
From a classification perspective, this vulnerability aligns with CWE-22 Improper Limitation of a Pathname to a Restricted Directory, which describes flaws where software does not properly neutralize special elements within file paths that can resolve to directories outside of the intended restricted directory. It also relates to CWE-436 Interpretation Conflict and CWE-79 Cross-site Scripting in cases where the written files are subsequently rendered by web components. In terms of offensive security frameworks, this exploit maps directly to MITRE ATT&CK technique T1059 Command and Scripting Interpreter if used for execution, or more accurately T1204 User Execution when leveraging stored XSS vectors, as well as T1567 Data Staged via Web Services if the file is written to a web-accessible location. Addressing this issue requires both immediate patching and long-term architectural reviews of input validation strategies across all database integration nodes within the application ecosystem.