IBM Langflow up to 1.10.1 Public Flow Build Endpoint /api/v1/build_public_tmp validate_public_flow_no_code_execution incomplete blacklist

Summaryinfo

A vulnerability was found in IBM Langflow up to 1.10.1. It has been rated as critical. This affects the function validate_public_flow_no_code_execution of the file /api/v1/build_public_tmp of the component Public Flow Build Endpoint. Performing a manipulation results in incomplete blacklist. This vulnerability was named CVE-2026-13448. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability classified as critical has been found in IBM Langflow up to 1.10.1. This affects the function validate_public_flow_no_code_execution of the file /api/v1/build_public_tmp of the component Public Flow Build Endpoint. The manipulation with an unknown input leads to a incomplete blacklist vulnerability. CWE is classifying the issue as CWE-184. The product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are not allowed by policy or otherwise require other action to neutralize before additional processing takes place, but the list is incomplete, leading to resultant weaknesses. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

IBM Langflow OSS 1.0.0 through 1.10.1 Lanflow OSS contains an unauthenticated remote code execution vulnerability in the public flow build endpoint ( /api/v1/build_public_tmp/{flow_id}/flow ). The vulnerability stems from an incomplete denylist in the validate_public_flow_no_code_execution() function that fails to block several code-execution agent components including OpenDsStarAgent, CodeActAgentSmolagents, and CSVAgent.

The advisory is shared at ibm.com. This vulnerability is uniquely identified as CVE-2026-13448 since 06/26/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details are known, but no exploit is available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 07/18/2026). MITRE ATT&CK project uses the attack technique T1562.006 for this issue.

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

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-45308). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

• IBM

Name

• Langflow

Version

• 1.10.0
• 1.10.1

License

• commercial

Website

• Vendor: https://www.ibm.com/

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

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