CVE-2026-19300: Langflow Information Disclosure Vulnerability

CVE-2026-19300 Overview

IBM Langflow OSS versions 1.0.0 through 1.11.2 contain an information disclosure vulnerability. The flaw stems from incomplete scrubbing of sensitive credential fields, allowing a remote unauthenticated attacker to obtain sensitive information over the network. The vulnerability is tracked under CWE-200: Exposure of Sensitive Information to an Unauthorized Actor.

Langflow is a visual framework for building agentic and retrieval-augmented generation (RAG) applications on top of large language models. Credential fields in Langflow typically hold API keys, database strings, and third-party service secrets used by AI workflows. Incomplete redaction of these fields exposes production secrets to any actor able to reach the affected endpoint.

Critical Impact
Remote unauthenticated attackers can retrieve sensitive credentials from Langflow deployments, potentially enabling downstream compromise of connected LLM providers, databases, and cloud services.

Affected Products

IBM Langflow OSS versions 1.0.0 through 1.11.2
Deployments on Apple macOS, Linux, and Microsoft Windows hosts
Any AI workflow or agent leveraging stored credential components in Langflow

Discovery Timeline

2026-09-04 - CVE-2026-19300 published to the National Vulnerability Database
2026-09-08 - Last updated in NVD database

Technical Details for CVE-2026-19300

Vulnerability Analysis

Langflow stores sensitive values (API keys, tokens, database credentials) in dedicated credential fields intended to be masked when flow definitions, logs, or API responses are returned to clients. The scrubbing routine that redacts these fields is incomplete. Certain code paths, serialization formats, or field types are not covered by the redaction logic, leaving raw secrets embedded in responses.

Because Langflow exposes an HTTP API and web UI over the network, an attacker able to reach the service can request flow definitions or related metadata and parse cleartext credentials from the response. No authentication or user interaction is required, and integrity or availability of the host is not affected.

Root Cause

The root cause is an incomplete implementation of credential sanitization logic. Sensitive field types added or modified between releases 1.0.0 and 1.11.2 were not consistently registered with the scrubbing routine. As a result, serialization of flow objects can emit secret material that should have been masked before transmission.

Attack Vector

The attacker interacts with the Langflow HTTP interface over the network. By requesting flow definitions, component metadata, or exported configurations, the attacker receives responses containing unredacted credential values. Exploitation requires no privileges, no user interaction, and can be automated against internet-exposed Langflow instances. The recovered credentials can then be used to pivot into upstream LLM providers, vector databases, or cloud accounts referenced by the flow.

No verified public proof-of-concept is available at the time of publication. See the IBM Support Page for vendor technical details.

Detection Methods for CVE-2026-19300

Indicators of Compromise

Unauthenticated HTTP GET requests to Langflow API endpoints that return flow, component, or export data from external or unexpected source IP addresses.
Outbound authentication events to third-party APIs (OpenAI, Anthropic, cloud providers, databases) originating from hosts or accounts that do not normally use those credentials.
Access log entries showing enumeration of Langflow flow IDs or bulk export endpoints in a short time window.

Detection Strategies

Inspect Langflow API responses in a staging environment for cleartext values in fields expected to be masked (for example, values not rendered as **********).
Alert on any access to Langflow management endpoints from outside the trusted management network.
Correlate credential use across identity providers and SaaS APIs to detect keys sourced from Langflow being used from new geographies or ASNs.

Monitoring Recommendations

Enable and centralize Langflow application logs, including request paths, source IPs, and response sizes, in a SIEM for anomaly detection.
Rotate all secrets referenced by Langflow flows and monitor the retired keys for any continued use, which indicates prior exfiltration.
Monitor egress traffic from the Langflow host for unexpected connections to credential harvesting infrastructure.

How to Mitigate CVE-2026-19300

Immediate Actions Required

Upgrade IBM Langflow OSS to a fixed release as documented on the IBM Support Page.
Rotate every credential, API key, and token stored in Langflow credential fields on affected versions, treating them as disclosed.
Remove Langflow from direct internet exposure and place it behind an authenticated reverse proxy or VPN.
Audit access logs for the affected version range for anomalous requests to flow and component endpoints.

Patch Information

IBM has published remediation guidance for Langflow OSS versions 1.0.0 through 1.11.2 on the IBM Support Page. Apply the vendor-recommended fixed release, then verify that credential fields are consistently masked in all API responses and exported flow definitions.

Workarounds

Restrict network access to the Langflow service to trusted management subnets using host firewalls or network ACLs.
Enforce authentication and authorization in front of Langflow via a reverse proxy until the patch can be applied.
Store secrets in an external secret manager and reference them at runtime rather than persisting them in Langflow credential fields.
Remove or replace any credential fields containing production secrets on vulnerable instances until upgrade is complete.

bash

# Configuration example: restrict Langflow to localhost and require reverse-proxy auth
# 1. Bind Langflow to loopback only
export LANGFLOW_HOST=127.0.0.1
export LANGFLOW_PORT=7860

# 2. Restrict inbound access at the host firewall (Linux/iptables)
iptables -A INPUT -p tcp --dport 7860 -s 127.0.0.1 -j ACCEPT
iptables -A INPUT -p tcp --dport 7860 -j DROP