CVE-2026-9138
MediumCVSS 6.5Exploitation Probability (EPSS)
Low risk22th percentile - higher than 22% of all known CVEs
Summary
IBM Langflow OSS versions 1.0.0 through 1.11.2 could allow an authenticated attacker to write arbitrary files to the server due to improper input validation in the SaveToFileComponent. The application constructs local file paths using attacker-controlled input without sufficient sanitization when handling requests to the /api/v1/run/{flow_id} endpoint. An attacker with low-privileged authenticated access (such as a valid API key or user session) can supply crafted path values, including absolute paths or path traversal sequences, allowing arbitrary file writes to locations writable by the Langflow process. Successful exploitation may lead to unauthorized file creation or modification, potentially resulting in further compromise depending on the deployment environment.
Risk Assessment
An attacker can write or modify files on the server, potentially leading to system integrity compromise and, in extreme cases, remote code execution.
Recommendation
Upgrade IBM Langflow OSS to a patched version and restrict access to the /api/v1/run/{flow_id} endpoint to trusted users only.
Other vulnerabilities in IBM Langflow OSS
See all- CVE-2026-12944Critical
IBM Langflow OSS 1.0.0 through 1.10.0 allows attackers to execute arbitrary Python code with root privileges (UID=0) on the Langflow server by submitting components containing socket or urllib imports. This enables AWS credential theft via IMDSv1 SSRF, arbitrary file exfiltration from the container filesystem, and lateral movement to internal services (PostgreSQL, Redis) within the Docker network. The scanner incorrectly returns "validated": true, providing a false security signal.
- CVE-2026-81204Critical
IBM Langflow OSS versions 1.0.0 through 1.11.5 allow a remote attacker to execute arbitrary code due to code injection during graph construction.
- CVE-2026-79724Critical
IBM Langflow OSS versions 1.0.0 through 1.11.5 allow a remote attacker to execute arbitrary OS commands due to improper neutralization of special elements used in an OS command.
- CVE-2026-85025Critical
IBM Langflow OSS versions 1.0.0 through 1.11.5 allow an unauthenticated attacker to execute arbitrary code and access or modify chat sessions through publicly shared MCP project endpoints due to improper enforcement of public-flow security restrictions and session isolation controls.
- CVE-2026-19295Critical
IBM Langflow OSS versions 1.0.0 through 1.11.1 allow an authenticated attacker to execute arbitrary operating system commands in the server process by saving a flow with a crafted type field value and triggering a build of a wrapper flow that references it. This allows privilege escalation from 'authenticated flow user' to arbitrary OS-level command execution, bypassing the LANGFLOW_ALLOW_CUSTOM_COMPONENTS=false policy.
- CVE-2026-19286Critical
IBM Langflow OSS versions 1.0.0 through 1.11.1 could allow a remote attacker to execute arbitrary code due to improper enforcement of security restrictions on the A2A public endpoint.
- CVE-2026-19297Critical
IBM Langflow OSS 1.0.0 through 1.9.6 could allow a remote attacker to obtain unauthorized access to user accounts due to improper restriction of excessive authentication attempts.
- CVE-2026-12946Critical
IBM Langflow OSS versions 1.0.0 through 1.10.0 could allow a remote attacker to inject arbitrary code on the system due to improper control of user input code.
- CVE-2026-13435Critical
IBM Langflow OSS versions 1.0.0 through 1.10.1 contain an improper input validation vulnerability in the PythonREPL sandbox implementation.
- CVE-2026-12940Critical
IBM Langflow OSS versions 1.0.0 through 1.10.1 are vulnerable to unauthenticated remote code execution via environment variable injection in the MCP stdio launcher. The vulnerability is due to an incomplete blocklist of dangerous environment variables (missing SHELLOPTS, BASHOPTS, and PS4) in src/lfx/src/lfx/base/mcp/util.py.
Original NVD description (English source)
IBM Langflow OSS 1.0.0 through 1.11.2 Langflow could allow an authenticated attacker to write arbitrary files to the server due to improper input validation in the SaveToFileComponent. The application constructs local file paths using attacker‑controlled input without sufficient sanitization when handling requests to the /api/v1/run/{flow_id} endpoint. An attacker with low‑privileged authenticated access (such as a valid API key or user session) can supply crafted path values, including absolute paths or path traversal sequences, allowing arbitrary file writes to locations writable by the Langflow process. Successful exploitation may lead to unauthorized file creation or modification, potentially resulting in further compromise depending on the deployment environment.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS