CVE-2026-73484 in Flowise
Summary
by MITRE • 08/13/2026
Flowise before 3.1.3 contains a sandbox escape vulnerability in pythonCodeValidator.ts that fails to block native Pandas DataFrame methods like to_csv, to_json, pipe, and query. Authenticated attackers can exploit this to exfiltrate uploaded CSV data or write arbitrary files to the server filesystem.
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Analysis
by VulDB Data Team • 08/13/2026
The vulnerability exists within Flowise version 3.1.2 and earlier, specifically in the pythonCodeValidator.ts component that is responsible for validating Python code executed within the application's sandbox environment. This security flaw represents a critical sandbox escape vulnerability that undermines the fundamental security boundaries designed to isolate potentially malicious code execution. The vulnerability stems from an incomplete validation mechanism that fails to properly restrict access to native Pandas DataFrame methods including to_csv, to_json, pipe, and query functions. These methods when invoked can provide direct access to file system operations and data exfiltration capabilities that bypass the intended security controls.
The technical implementation of this vulnerability allows authenticated attackers to craft Python code that leverages these restricted DataFrame methods to perform unauthorized operations on the underlying system. When an attacker uploads CSV data and subsequently executes malicious Python code through the vulnerable validation process, they can utilize functions like to_csv to write data to arbitrary file paths on the server filesystem or use to_json to serialize and potentially exfiltrate sensitive information. The pipe method can be exploited to chain commands that bypass the sandbox restrictions, while query functionality enables complex data manipulation operations that may reveal or alter system data. This vulnerability directly maps to CWE-94, which describes "Improper Control of Generation of Code" where code is generated or executed in a way that allows arbitrary code execution, and specifically relates to CWE-78, "Improper Neutralization of Special Elements used in OS Command Injection."
The operational impact of this vulnerability extends beyond simple data theft, as authenticated attackers with access to the Flowise application can establish persistent footholds on the server through file writing capabilities. The ability to write arbitrary files to the filesystem enables attackers to deploy backdoors, modify application behavior, or escalate privileges within the system. Data exfiltration becomes possible through CSV data manipulation and serialization methods, potentially exposing sensitive information stored in uploaded datasets. This vulnerability is particularly concerning in environments where Flowise serves as a data processing platform for confidential information, as it provides a direct pathway for attackers to bypass application-level security controls and access underlying infrastructure.
Mitigation strategies for this vulnerability require immediate patching of Flowise to version 3.1.3 or later where the pythonCodeValidator.ts component properly restricts access to dangerous DataFrame methods. Organizations should implement additional security measures including network segmentation to limit access to Flowise installations, comprehensive monitoring of file system operations, and regular security assessments of code execution environments. The principle of least privilege should be enforced through strict user access controls and application hardening techniques that further isolate the execution environment. Security teams should also consider implementing runtime application self-protection mechanisms or additional input validation layers to detect and prevent exploitation attempts. Organizations with critical data processing workloads should conduct thorough vulnerability assessments and penetration testing to identify potential attack vectors that may leverage similar sandbox escape techniques as outlined in the ATT&CK framework under T1059.006 for Python-based execution and T1566 for credential access through application vulnerabilities.