Security Bulletin
Summary
Langflow contains an authorization policy bypass vulnerability that allows a non-superuser authenticated attacker to execute arbitrary Python code as the Langflow service identity despite the LANGFLOW_CUSTOM_COMPONENT_ADMIN_ONLY=true security control. The dedicated custom component API correctly enforces the administrator-only boundary and returns HTTP 403 to non-superusers; however, the authenticated flow-build endpoint accepts inline graph data containing attacker-controlled component code and neither the flow validation nor the trusted-code resolution functions evaluate the administrator-only setting or the caller's superuser status before the code reaches the Python compiler and execution layer. An attacker with a valid non-superuser account who owns a flow can inject and execute arbitrary Python, gaining access to application secrets, environment variables, files, network destinations, and all resources accessible to the Langflow service account.
Vulnerability Details
CVEID: CVE-2026-19298
DESCRIPTION: Langflow OSS could allow a remote authenticated attacker to execute arbitrary code due to an authorization bypass in the flow build process.
CWE: CWE-94: Improper Control of Generation of Code ('Code Injection')
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 | 1.0.0-1.11.2 |
Remediation/Fixes
IBM strongly recommends addressing the vulnerability now by upgrading Langflow OSS to version 1.11.3
Workarounds and Mitigations
None
Get Notified about Future Security Bulletins
References
Acknowledgement
Change History
28 Aug 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:
28 August 2026
Initial Publish date:
28 August 2026
UID
ibm17285640