Security Bulletin
Summary
Langflow uses a local and S3-backed storage service to manage files uploaded by users and referenced by flow components. The flow execution runtime accepts attacker-controlled file paths through the tweaks API without invoking the path containment guard, allowing traversal sequences to escape the configured data directory. An authenticated user can also supply another user's storage namespace as a component file input, reading files belonging to other users in multi-user deployments. Additionally, when S3 storage is configured alongside the LANGFLOW_RESTRICT_LOCAL_FILE_ACCESS hardening flag, a code path that detects pre-existing local files bypasses the confinement check entirely, rendering the flag ineffective and exposing files outside the permitted storage directory, including the application secret key used to encrypt stored credentials.
Vulnerability Details
CVEID: CVE-2026-9596
DESCRIPTION:
CWE: CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
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)
CVEID: CVE-2026-79725
DESCRIPTION: Langflow OSS could allow a remote authenticated attacker to read arbitrary files due to improper access control.
CWE: CWE-284: Improper Access Control
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)
CVEID: CVE-2026-9225
DESCRIPTION: Langflow could allow an authenticated attacker to access sensitive files belonging to other users due to improper access control in the File/Read File component. When executing flows through the /api/v1/run/advanced/{flow_id} endpoint, the application allows component inputs to reference storage paths using arbitrary user or flow identifiers without verifying ownership. An attacker with low‑privileged authenticated access can supply a crafted file path pointing to another user’s storage namespace, causing the backend to read and return the contents of files uploaded by other users. This vulnerability bypasses intended authorization checks enforced by the file management API and may result in unauthorized disclosure of sensitive user data.
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 OSS | 1.0.0-1.11.5 |
Remediation/Fixes
IBM strongly recommends addressing the vulnerability now by upgrading Langflow OSS to version 1.11.6
Workarounds and Mitigations
None
Get Notified about Future Security Bulletins
References
Acknowledgement
Change History
08 Sep 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:
08 September 2026
Initial Publish date:
08 September 2026
UID
ibm17286657