Security Bulletin
Summary
The Python Interpreter component and legacy Python REPL Tool component provided flow and agent authors the ability to execute Python code within a scoped globals environment restricted to an operator-configured import allow-list and curated safe builtins. An attacker who could provide input to a deployed flow, agent, or permitted run path invoking either component could supply code that bypassed the validator. An attacker who successfully exploited this bypass could read sensitive values present in the server process environment and in-memory application settings, including provider API keys, database credentials, and the symmetric signing and encryption key material used for JSON Web Token (JWT) issuance and for encrypting stored credential variables. Under the default HS256 JWT configuration, exposure of that key material could allow the attacker to forge a valid access token for a known user identifier and to decrypt stored encrypted credentials.
Vulnerability Details
CVEID: CVE-2026-13435
DESCRIPTION: Langflow OSS contains an improper input validation vulnerability in the PythonREPL sandbox implementation.
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)
Affected Products and Versions
| Affected Product(s) | Version(s) |
| Langflow OSS | 1.0.0-1.10.1 |
Remediation/Fixes
IBM strongly recommends addressing the vulnerability now by upgrading Langflow OSS to version 1.10.2
Workarounds and Mitigations
None
Get Notified about Future Security Bulletins
References
Acknowledgement
Change History
14 Jul 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:
14 July 2026
Initial Publish date:
14 July 2026
UID
ibm17279987