langflow-ai Langflow up to 1.8.4 Knowledge Base Creation Endpoint knowledge_bases.py path traversal

Summaryinfo

A vulnerability identified as critical has been detected in langflow-ai Langflow up to 1.8.4. Affected by this vulnerability is the function knowledge_bases-create_knowledge_base-a-live-http-post-to-create-knowledge-base of the file src/backend/base/langflow/api/v1/knowledge_bases.py of the component Knowledge Base Creation Endpoint. The manipulation leads to path traversal. This vulnerability is documented as CVE-2026-51888. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability, which was classified as critical, has been found in langflow-ai Langflow up to 1.8.4. This issue affects the function knowledge_bases-create_knowledge_base-a-live-http-post-to-create-knowledge-base of the file src/backend/base/langflow/api/v1/knowledge_bases.py of the component Knowledge Base Creation Endpoint. The manipulation with an unknown input leads to a path traversal vulnerability. Using CWE to declare the problem leads to CWE-22. The product 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 product 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. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

langflow-ai langflow v1.8.4 is affected by: Directory Traversal. The impact is: Arbitrary file write outside the intended workspace or storage boundary.. The component is: src/backend/base/langflow/api/v1/knowledge_bases.py:knowledge_bases-create_knowledge_base-a-live-http-post-to-create-knowledge-base. The attack vector is: Attack surface: HTTP or browser-backed service path. A public-facing upload or HTTP route handler forwards an attacker-controlled path or filename into host file creation without any visible boundary enforcement. ¶¶ A weakness has been identified in langflow-ai langflow up to 1.8.4. langflow contains an absolute path traversal vulnerability in knowledge_bases-create_knowledge_base-a-live-http-post-to-create-knowledge-base (src/backend/base/langflow/api/v1/knowledge_bases.py:51). An attacker can write or overwrite files outside the intended working directory by providing absolute paths in the knowledge base creation endpoint.

The advisory is shared at gist.github.com. The identification of this vulnerability is CVE-2026-51888 since 06/08/2026. The exploitation is known to be easy. The attack may be initiated remotely. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/02/2026). MITRE ATT&CK project uses the attack technique T1006 for this issue.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Type

• Artificial Intelligence Software

Vendor

• langflow-ai

Name

• Langflow

Version

• 1.8.0
• 1.8.1
• 1.8.2
• 1.8.3
• 1.8.4

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CPE 2.2info

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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