CVE-2026-55450
CriticalCVSS 9.3Exploitation Probability (EPSS)
Low risk22th percentile - higher than 22% of all known CVEs
Summary
Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to version 1.9.1, unauthenticated users can upload unlimited amounts of data to the server, leading to space exhaustion. Additionally, the server response reveals the absolute path of the uploaded file, which constitutes an information leak.
Risk Assessment
The organization may face availability issues due to server space exhaustion. The information leak regarding file paths could facilitate attacks on other system components.
Recommendation
It is recommended to upgrade to version 1.9.1 or later to mitigate this vulnerability. Additionally, implementing restrictions on data uploads by unauthenticated users is advisable.
Other vulnerabilities in Langflow
See all- CVE-2026-34046High
Langflow prior to version 1.5.1 had a security vulnerability that allowed authenticated users to access other users' flows without ownership checks. The issue stemmed from the lack of proper query filtering based on the `AUTO_LOGIN` setting.
- CVE-2026-55255HighActively exploited
In Langflow prior to 1.9.1, an IDOR vulnerability in the /api/v1/responses endpoint allows an authenticated attacker to execute any flow belonging to another user by specifying the victim's flow ID in the request.
- CVE-2026-42048Critical
Langflow, a tool for building and deploying AI agents, is vulnerable to Path Traversal in the Knowledge Bases API (DELETE /api/v1/knowledge_bases) prior to version 1.9.0. An attacker can exploit this flaw to delete arbitrary directories on the server.
- CVE-2026-33017CriticalActively exploited
Langflow is a tool for building and deploying AI-powered agents and workflows. In versions prior to 1.9.0, the POST /api/v1/build_public_tmp/{flow_id}/flow endpoint allowed building public flows without requiring authentication, leading to the possibility of remote code execution by unauthorized users.
- CVE-2026-0770CriticalActively exploited
A vulnerability in Langflow allows remote code execution via the exec_globals parameter in the validate endpoint. An unauthenticated attacker can inject malicious code from an untrusted source.
- CVE-2026-21445Critical
Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to version 1.7.0.dev45, multiple critical API endpoints in Langflow are missing authentication controls. The issue allows any unauthenticated user to access sensitive user conversation data, transaction histories, and perform destructive operations including message deletion. This affects endpoints handling personal data and system operations that should require proper authorization. Version 1.7.0.dev45 contains a patch.
- CVE-2025-34291HighActively exploited
A vulnerability in Langflow versions up to and including 1.6.9 enables account takeover and remote code execution. An overly permissive CORS configuration (allow_origins='*' with allow_credentials=True) combined with a refresh token cookie set as SameSite=None allows a malicious webpage to perform cross-origin requests with credentials and call the refresh endpoint. An attacker can obtain fresh access_token/refresh_token pairs for a victim session and use them to execute arbitrary code, leading to full system compromise.
- CVE-2025-3248CriticalActively exploited
Langflow versions prior to 1.3.0 are vulnerable to code injection via the /api/v1/validate/code endpoint. An unauthenticated remote attacker can execute arbitrary code by sending crafted HTTP requests.
- CVE-2026-51888Low risk· EPSS 13%
Directory Traversal vulnerability in langflow up to 1.8.4. Through the knowledge base creation endpoint, an attacker can write or overwrite files outside the intended working directory using absolute paths.
- CVE-2026-51886Low risk· EPSS 6%
Code Injection vulnerability in langflow up to 1.9.3. An authenticated attacker can execute arbitrary Python code on the server by submitting malicious code to the /api/v1/validate/code endpoint, which executes code without sandboxing.
Original NVD description (English source)
Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to 1.9.1, unauthenticated users can upload any amount of data to the server without any limitations. No need for any prior knowledge, only network access to Langflow. This can lead to space exhaustion on the server. In addition, in the response, the absolute path of the uploaded file is reported to the attacker, which is an information leak that can assist in chaining other primitives. This vulnerability is fixed in 1.9.1.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS