IBM Langflow OSS 1.0.0-1.11.2 Auth File Write via SaveToFileComp
CVE-2026-9138 Published on September 4, 2026

Langflow is vulnerable to arbitrary file write and arbitrary file deletion due to unvalidated paths in file-processing components
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 attackercontrolled input without sufficient sanitization when handling requests to the /api/v1/run/{flow_id} endpoint. An attacker with lowprivileged 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.

Vendor Advisory NVD

Vulnerability Analysis

CVE-2026-9138 is exploitable with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality, a high impact on integrity, and no impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
LOW
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
NONE
Integrity Impact:
HIGH
Availability Impact:
NONE

Weakness Type

What is a Directory traversal Vulnerability?

The software uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the software does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.

CVE-2026-9138 has been classified to as a Directory traversal vulnerability or weakness.


Products Associated with CVE-2026-9138

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IBM Langflow Oss
 

Affected Versions

IBM Langflow OSS: