Security Bulletin
Summary
A rate limiting capability exists within the product to restrict the number of authentication attempts permitted per IP address per minute against the login endpoint (POST /api/v1/login). This control is configurable via the LANGFLOW_RATE_LIMIT_ENABLED environment variable, which defaults to true with a limit of 5 attempts per minute per IP using in-memory storage. In deployments where this control is explicitly disabled by an administrator, or in environments where the default configuration has not been validated post-deployment, an attacker who has network access to the login endpoint could submit unlimited credential guesses at full network speed, enabling brute force or credential stuffing attacks against user accounts. A victim whose account credentials are weak or who has not changed default credentials could have their account compromised, granting the attacker the same level of access as the targeted user, up to and including full superuser privileges on the system.
Vulnerability Details
CVEID: CVE-2026-19297
DESCRIPTION: Langflow OSS could allow a remote attacker to obtain unauthorized access to user accounts due to improper restriction of excessive authentication attempts.
CWE: CWE-307: Improper Restriction of Excessive Authentication Attempts
CVSS Source: IBM
CVSS Base score: 9.1
CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N)
Affected Products and Versions
| Affected Product(s) | Version(s) |
| Langflow OSS | 1.0.0-1.9.6 |
Remediation/Fixes
IBM recommends addressing the vulnerability now by upgrading to Langflow OSS 1.10.0 or newer https://pypi.org/project/langflow/
Workarounds and Mitigations
None
Get Notified about Future Security Bulletins
References
Acknowledgement
Change History
12 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:
12 August 2026
Initial Publish date:
12 August 2026
UID
ibm17283558