CVE-2026-34046
HighCVSS 8.8Exploitation Probability (EPSS)
Low risk41th percentile - higher than 41% of all known CVEs
Summary
Langflow prior to version 1.5.1 contains a vulnerability in the _read_flow helper in src/backend/base/langflow/api/v1/flows.py where, with authentication enabled (AUTO_LOGIN False), no ownership check was enforced. An authenticated user could read, modify, or delete other users' flows, including embedded API keys.
Risk Assessment
Unauthorized access to other users' flows, disclosure of API keys, modification of AI agent logic, and deletion of flows are possible, compromising confidentiality and integrity.
Recommendation
Upgrade Langflow to version 1.5.1 or later, which removes the AUTO_LOGIN conditional and unconditionally scopes queries to the requesting user.
Other vulnerabilities in Langflow
See all- CVE-2026-105740Critical
Langflow before 1.9.0 allows any authenticated user to achieve Remote Code Execution (RCE) on the server by adding an MCP server with the "Stdio" transport. The user-supplied command field is passed directly to bash -c "exec {command}" with zero validation, no allowlisting, and no sandboxing. The command executes immediately when the server list is fetched. Additionally, the env field allows arbitrary environment variable injection (e.g., LD_PRELOAD, PATH override).
- CVE-2026-105697Critical
Langflow before 1.10.3 launches whatever command / args a user put in an MCP server configuration, with no allowlist and (before 1.10.3) wrapped in bash -c "exec {command} ...". Any user able to reach the MCP server settings or to build a flow with the MCP Tools component could add a "server" whose command is an arbitrary OS command. The command runs on the Langflow host as the Langflow process user as soon as Langflow tries to connect to the server. With the default LANGFLOW_AUTO_LOGIN=true, GET /api/v1/auto_login hands out a token without credentials, so on an exposed instance running the default configuration this is reachable without an account. With AUTO_LOGIN disabled, any authenticated (non-admin) user can exploit it.
- CVE-2026-51886Critical
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.
- CVE-2026-55450Critical
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.
- 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-2025-68478High
Langflow prior to version 1.7.0 allows an arbitrary path to be specified in the request body's fs_path, causing the server to serialize the Flow object into JSON and create or overwrite a file at that path. There is no path restriction, normalization, or allowed directory enforcement, so absolute paths (e.g., /etc/poc.txt) are interpreted as is.
Original NVD description (English source)
Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to version 1.5.1, the `_read_flow` helper in `src/backend/base/langflow/api/v1/flows.py` branched on the `AUTO_LOGIN` setting to decide whether to filter by `user_id`. When `AUTO_LOGIN` was `False` (i.e., authentication was enabled), neither branch enforced an ownership check — the query returned any flow matching the given UUID regardless of who owned it. This allowed any authenticated user to read any other user's flow, including embedded plaintext API keys; modify the logic of another user's AI agents, and/or delete flows belonging to other users. The vulnerability was introduced by the conditional logic that was meant to accommodate public/example flows (those with `user_id = NULL`) under auto-login mode, but inadvertently left the authenticated path without an ownership filter. The fix in version 1.5.1 removes the `AUTO_LOGIN` conditional entirely and unconditionally scopes the query to the requesting user.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS