Security Bulletin
Summary
Langflow OSS is affected by multiple vulnerabilities involving remote code execution and security scanner controls. Depending on the affected feature and deployment configuration, an authenticated attacker could bypass component security scanning, inject callback arguments, execute arbitrary class definitions, or execute commands through the agent communication endpoint.
Vulnerability Details
CVEID: CVE-2026-107366
DESCRIPTION: Three message endpoints perform no ownership verification. Any authenticated user can bulk-delete another user's messages, overwrite message content to inject malicious prompts, or hijack an entire conversation session by reassigning its session ID.
CWE: CWE-639: Authorization Bypass Through User-Controlled Key
CVSS Source: IBM
CVSS Base score: 8.3
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L)
CVEID: CVE-2026-90991
DESCRIPTION: Langflow OSS could allow a remote authenticated attacker to cause a denial of service due to allocation of resources without limits or throttling.
CWE: CWE-770: Allocation of Resources Without Limits or Throttling
CVSS Source: IBM
CVSS Base score: 6.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
CVEID: CVE-2026-110190
DESCRIPTION: Langflow OSS could allow an authenticated user to traverse directories on the system. An attacker could
send a specially crafted URL request to view arbitrary files on the system.
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-2026-110244
DESCRIPTION: Langflow OSS could allow a remote authenticated attacker to obtain sensitive information 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: 6.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
CVEID: CVE-2026-110200
DESCRIPTION: Langflow OSS could allow a remote authenticated attacker to obtain sensitive information due to cleartext storage of sensitive information.
CWE: CWE-312: Cleartext Storage of Sensitive Information
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-2026-110245
DESCRIPTION: Langflow OSS could allow a remote attacker to obtain sensitive information due to improper authentication.
CWE: CWE-287: Improper Authentication
CVSS Source: IBM
CVSS Base score: 7.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N)
CVEID: CVE-2026-77817
DESCRIPTION: Langflow OSS could allow a remote authenticated attacker to obtain sensitive information due to improper sanitization of secrets during flow and project exports.
CWE: CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
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-2026-18894
DESCRIPTION: Langflow OSS could allow a remote attacker to trigger pre-existing stored Python component code in a public workflow, executing it under the flow owner's runtime context within the server process. This bypasses the intended trust boundary where public execution paths are restricted to server-trusted component code.
CWE: CWE-94: Improper Control of Generation of Code ('Code Injection')
CVSS Source: IBM
CVSS Base score: 6.5
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N)
CVEID: CVE-2026-110196
DESCRIPTION: Langflow OSS could allow a remote attacker with a low-privileged authenticated account to bypass the administrator-only restriction and execute arbitrary code on the server by configuring a built-in code-execution component with attacker-supplied inputs.
CWE: CWE-862: Missing Authorization
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)
ID: CVE-2026-107328
DESCRIPTION: Langflow OSS could allow a remote authenticated attacker to execute arbitrary code due to improper neutralization of code in eval/exec.
CWE: CWE-94: Improper Control of Generation of Code ('Code 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)
ID: CVE-2026-107329
DESCRIPTION: Langflow OSS could allow a remote authenticated attacker to execute arbitrary code due to improper control of code generation.
CWE: CWE-94: Improper Control of Generation of Code ('Code 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)
ID: CVE-2026-107326
DESCRIPTION: Langflow OSS could allow a remote authenticated attacker to execute arbitrary code due to improper neutralization of special elements used in an OS command.
CWE: CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command 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)
ID: CVE-2026-107327
DESCRIPTION: Langflow OSS could allow a remote authenticated attacker to execute arbitrary code due to missing authorization.
CWE: CWE-862: Missing Authorization
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)
ID: CVE-2026-110309
DESCRIPTION: Langflow OSS could allow a remote authenticated attacker to execute arbitrary commands due to improper control of code generation.
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 - 1.12.4 |
Remediation/Fixes
IBM strongly recommends addressing the vulnerability now by upgrading Langflow OSS to version 1.12.5.
For Langflow OSS versions 1.0.0 - 1.12.4, follow the Prepare to upgrade instructions and release-specific configuration changes, including backing up your existing installation, then follow the Langflow OSS installation instructions to install version 1.12.5 and test your flows. For deployments using MCP stdio, also apply the configuration controls in Workarounds and Mitigations.
This bulletin also discloses fixes delivered in prior releases: CVE-2026-107366 was fixed in version 1.9.0; CVE-2026-18894 was fixed in version 1.11.2; and CVE-2026-77817 was fixed in version 1.11.5. Version 1.12.5 includes these fixes.
Workarounds and Mitigations
IBM strongly recommends applying the following configuration controls to deployments using MCP stdio in addition to upgrading Langflow OSS to version 1.12.5. These controls do not replace the upgrade.
Set LANGFLOW_MCP_SERVER_INTERPRETER_HARDENING=true to reject direct shell-script execution, and set LANGFLOW_CUSTOM_COMPONENT_ADMIN_ONLY=true to block non-admin MCP stdio access. Restart the Langflow service after updating its environment configuration. These restrictions can require changes to existing MCP server launch configurations and limit which users can use MCP stdio.
For public workflows, retain the default restriction on custom components. Explicitly enabling LANGFLOW_ALLOW_PUBLIC_CUSTOM_COMPONENTS permits custom component execution and changes the default protection described for CVE-2026-18894.
For CVE-2026-77817, upgrading prevents the identified secret disclosure in new flow and project exports. Revoke or rotate any credentials exposed in previously exported files; upgrading does not remove secrets from copies already exported.
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References
Acknowledgement
Change History
19 Oct 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:
19 October 2026
Initial Publish date:
19 October 2026
UID
ibm17293016