Security Bulletin
Summary
A path traversal vulnerability existed in two independent file handling mechanisms used by the product's workflow execution and file management capabilities. The file upload endpoint accepted multipart filenames directly from HTTP request metadata without sanitization, allowing an authenticated attacker to supply directory traversal sequences in the Content-Disposition filename field and cause files to be written outside the intended user-scoped storage boundary. Separately, a file-writing workflow component accepted a user-controlled file name parameter that was expanded without path containment enforcement, allowing an attacker with the ability to execute or configure a workflow containing this component to write arbitrary content to any path accessible to the server process. Both vectors required a valid Application Programming Interface (API) key but no additional victim interaction. A successful exploit of either vector could allow the attacker to overwrite sensitive server files, plant malicious content, or corrupt application data depending on the privileges under which the server process operates.
Vulnerability Details
CVEID: CVE-2026-84889
DESCRIPTION: Langflow OSS could allow a remote authenticated attacker to execute arbitrary code due to improper limitation of a pathname to a restricted directory.
CWE: CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CVSS Source: IBM
CVSS Base score: 8.8
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
Affected Products and Versions
| Affected Product(s) | Version(s) |
| Langflow OSS | 1.0.0-1.10.3 |
Remediation/Fixes
IBM strongly recommends addressing the vulnerability now by upgrading Langflow OSS to version 1.11.0
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
ibm17286656