Security Bulletin
Summary
Langflow contains multiple vulnerabilities that allow arbitrary Python and operating system command execution on the server. The PythonFunction component lacks the runtime code-execution gate applied to other code-execution components, enabling an authenticated user to bypass the allow_custom_components=false hardening policy through the RunFlow component's private tweak channel, which filters only the literal field name "code" and does not enforce the same code-field blocking as the shared apply_tweaks path. A separate vulnerability in the create_input_schema_from_dict function allows attacker-controlled flow template type field strings to reach Pydantic's ForwardRef evaluation path, which internally calls eval() with an unrestricted builtins namespace, also bypassing the allow_custom_components=false policy without modifying any trusted code field. The Agent-to-Agent public execution path does not invoke the validate_public_flow_no_code_execution guard applied by other unauthenticated public execution surfaces, allowing an unauthenticated network caller to execute Python in the Langflow backend process when A2A is enabled and an auth_type=none agent flow is published.
Vulnerability Details
CVEID: CVE-2026-19286
DESCRIPTION: Langflow OSS could allow a remote attacker to execute arbitrary code due to improper enforcement of security restrictions on the A2A public endpoint.
CWE: CWE-94: Improper Control of Generation of Code ('Code Injection')
CVSS Source: IBM
CVSS Base score: 9.8
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-18729
DESCRIPTION: Langflow OSS could allow a remote authenticated attacker to execute arbitrary code due to improper control of generation of code.
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)
CVEID: CVE-2026-19295
DESCRIPTION: Langflow OSS allows an authenticated attacker to execute arbitrary operating system commands in the server process by saving a flow with a crafted type field value and triggering a build of a wrapper flow that references it. This allowed privilege escalation from "authenticated flow user" to arbitrary OS-level command execution under the server process identity, bypassing the LANGFLOW_ALLOW_CUSTOM_COMPONENTS=false policy control.
CWE: CWE-95: Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection')
CVSS Source: IBM
CVSS Base score: 9.9
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H)
Affected Products and Versions
| Affected Product(s) | Version(s) |
| Langflow OSS | 1.0.0-1.11.1 |
Remediation/Fixes
IBM strongly recommends addressing the vulnerability now by upgrading Langflow OSS to version 1.11.2
Workarounds and Mitigations
None
Get Notified about Future Security Bulletins
References
Acknowledgement
Change History
24 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:
24 August 2026
Initial Publish date:
24 August 2026
UID
ibm17284733