External risk intelligence

IBM Langflow OSS Auto-Login Vulnerability Grants Unauthenticated Administrative Access.

CVE advisorySeverity: CRITICAL (CVSS 9.8)

CVE-2026-9103

The vulnerability resides in an API endpoint commonly exposed in web applications and services. Because the affected product is designed as an interface that manages authentication and sessions, and the default configuration enables the vulnerable auto-login behavior, it is very likely to be reachable via public-facing internet services.

Missing Authentication

Halo Surface Signal: 5 out of 5 — more likely to be public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

IBM Langflow OSS, a platform for building and managing AI applications, has a critical security flaw in its auto-login feature. This vulnerability could allow unauthorized remote attackers to gain full administrative control over systems that use this software, potentially by bypassing authentication and accessing sensitive information.

Flaw allows unauthenticated access to admin controls.
Critical access vulnerability if auto-login is enabled.
Confirm relevance and assess potential unauthorized access.

Attack Path

How an attacker could exploit the issue

An attacker could gain unauthorized administrative access to IBM Langflow by exploiting a flaw in the automatic login feature. This feature, enabled by default, issues powerful access tokens without verifying the user's identity. Additionally, lenient security settings might expose these tokens to other websites, further increasing the risk of a breach.

No authentication required for initial access.
Triggered by accessing the auto-login API endpoint.
Results in full administrative control.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability could permit an unauthenticated attacker to gain full administrative access to the affected system. When the AUTO_LOGIN configuration is enabled, the /api/v1/login/auto_login endpoint issues superuser tokens without authentication, and permissive CORS settings might expose these tokens to unintended origins.

Unauthenticated administrative access to the system.
Exploitation via an unauthenticated network request.
Complete compromise of system control.

Operational Fix

Recommended remediation, mitigation, and detection steps

Application owners and infrastructure teams should prioritize identifying all instances of IBM Langflow OSS within their environment. Confirming exposure, business criticality, and the designated owner for each instance is the crucial first step before planning remediation.

Identify affected instances and owners.
Verify internet reachability and business criticality.
Plan remediation based on confirmed risk.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

Halo Threat Intelligence helps prioritize remediation with Halo Surface Signal and H/A/L/O context. Start exposure validation with a free external attack surface trial.

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Frequently asked questions

What is IBM Langflow OSS?

IBM Langflow OSS is a platform designed to help users build and manage AI applications. It serves as an interface for developers to create workflows and manage system sessions, which includes features for handling user authentication and administrative access.

What does CVE-2026-9103 mean in plain English?

This vulnerability is classified as CWE-306, which refers to a Missing Authentication for Critical Function. Specifically, the software's auto-login feature fails to verify who is requesting access. Because it trusts the request implicitly, it grants high-level 'superuser' administrative tokens to anyone who calls the affected API endpoint.

How is the auto-login vulnerability triggered?

An attacker can trigger this by sending a network request to the /api/v1/login/auto_login endpoint. This only succeeds when the AUTO_LOGIN configuration is enabled, which is the default setting for the software. If this configuration is disabled, the specific API endpoint does not issue the unauthorized superuser tokens.

How likely is CVE-2026-9103 to affect my network?

According to Halo Surface Signal, this vulnerability is very likely to be reachable if your instance is internet-facing. Because the flaw exists in an API endpoint commonly used for service communication and session management, systems exposed to the public internet are at higher risk of being reached by an external attacker.

What should I do first if I run IBM Langflow OSS?

Your first step is to perform an inventory to identify every instance of IBM Langflow OSS running in your environment. Once identified, verify if the AUTO_LOGIN configuration is active and determine whether those instances are accessible from the internet. Prioritize these systems for review to ensure administrative controls are not exposed to unauthorized users.

References

www.ibm.com/support/pages/node/7278926

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.