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Security Bulletin: Broken Access Control Vulnerabilities in Langflow 1.0.0 - 1.8.4 File Handling API Allowed Unauthorized Access to User Files

Security Bulletin


Summary

Two broken access control vulnerabilities in Langflow's file handling API allowed unauthorized access to user files. The first vulnerability (CVE-TBD-1) in the GET /api/v1/files/images/{flow_id}/{file_name} endpoint lacked authentication requirements, allowing any unauthenticated attacker with network access to download images from any flow. The second vulnerability (CVE-TBD-2) in the GET /api/v1/files/download/{flow_id}/{file_name} endpoint required authentication but did not properly enforce flow ownership validation, allowing any authenticated user to download files from other users' flows through an Insecure Direct Object Reference (IDOR) attack. In multi-tenant deployments, these vulnerabilities resulted in complete data isolation failure between users, exposing sensitive documents, images, and data files uploaded to private flows to unauthorized parties.

Vulnerability Details

CVEID:   CVE-2026-10700
DESCRIPTION:   Langflow OSS contains multiple broken access control vulnerabilities in its file handling API that allow unauthorized access to user files.The /api/v1/files/images/{flow_id}/{file_name} endpoint does not enforce authentication or authorization checks, allowing unauthenticated remote attackers to retrieve image files associated with any flow by specifying a valid flow_id and file_name.Additionally, the /api/v1/files/download/{flow_id}/{file_name} endpoint requires authentication but fails to properly validate ownership of the requested resource. As a result, an authenticated user can access files belonging to other users by supplying arbitrary identifiers, leading to an authorization bypass (IDOR).Successful exploitation may result in unauthorized disclosure of sensitive data, including files stored in private flows. This issue breaks tenant isolation in multi-user deployments.
CWE:   CWE-639: Authorization Bypass Through User-Controlled Key
CVSS Source:   IBM
CVSS Base score:   6.5
CVSS Vector:   (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N)

Affected Products and Versions

Affected Product(s)Version(s)
Langflow OSS1.0.0 - 1.8.4

Remediation/Fixes

IBM suggests users upgrade to Langflow v1.9.0 and later

Workarounds and Mitigations

None

Get Notified about Future Security Bulletins

References

Off

Acknowledgement

Sergio Cabrera (nekros1xx) https://www.linkedin.com/in/sergio-cabrera-878766239/

Change History

09 Jul 2026: Initial Publication

*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.

Disclaimer

According to the Forum of Incident Response and Security Teams (FIRST), the Common Vulnerability Scoring System (CVSS) is an "industry open standard designed to convey vulnerability severity and help to determine urgency and priority of response." IBM PROVIDES THE CVSS SCORES ""AS IS"" WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY. In addition to other efforts to address potential vulnerabilities, IBM periodically updates the record of components contained in our product offerings. As part of that effort, if IBM identifies previously unidentified packages in a product/service inventory, we address relevant vulnerabilities regardless of CVE date. Inclusion of an older CVEID does not demonstrate that the referenced product has been used by IBM since that date, nor that IBM was aware of a vulnerability as of that date. We are making clients aware of relevant vulnerabilities as we become aware of them. "Affected Products and Versions" referenced in IBM Security Bulletins are intended to be only products and versions that are supported by IBM and have not passed their end-of-support or warranty date. Thus, failure to reference unsupported or extended-support products and versions in this Security Bulletin does not constitute a determination by IBM that they are unaffected by the vulnerability. Reference to one or more unsupported versions in this Security Bulletin shall not create an obligation for IBM to provide fixes for any unsupported or extended-support products or versions.

Document Location

Worldwide

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Document Information

Modified date:
09 July 2026

Initial Publish date:
09 July 2026

UID

ibm17279675