CVE-2026-19294 Overview
CVE-2026-19294 is an improper authorization vulnerability [CWE-639] in IBM Langflow OSS versions 1.0.0 through 1.11.1. Langflow is an open-source framework for building agentic AI workflows and language model applications. The flaw allows a remote authenticated attacker to execute and read any user's private flow. The vulnerability stems from missing authorization checks on flow-access operations, enabling horizontal privilege escalation across tenant boundaries.
Critical Impact
Authenticated users can read and execute private flows belonging to other users, exposing proprietary logic, embedded credentials, and sensitive AI pipeline data.
Affected Products
- IBM Langflow OSS 1.0.0 through 1.11.1
- Deployments exposing multi-user Langflow instances
- Langflow SaaS or shared-tenant installations built on affected OSS releases
Discovery Timeline
- 2026-08-28 - CVE-2026-19294 published to NVD
- 2026-08-31 - Last updated in NVD database
Technical Details for CVE-2026-19294
Vulnerability Analysis
The vulnerability is an Insecure Direct Object Reference (IDOR) affecting Langflow's flow-management endpoints. Langflow assigns each stored flow a unique identifier and enforces authentication for API access. However, the affected versions do not verify that the requesting user owns the flow referenced by that identifier. An authenticated attacker who supplies another user's flow ID can retrieve the flow definition or trigger its execution.
Because Langflow flows commonly encapsulate prompts, model configurations, retrieval pipelines, tool integrations, and API keys, cross-tenant access exposes intellectual property and secrets. Execution of another user's flow can also invoke downstream integrations under the victim's context, resulting in unintended API calls and consumption of paid resources.
Root Cause
The root cause is a missing authorization check tied to the authenticated identity. The application authenticates the caller but does not evaluate whether that caller has rights to the specific flow object being accessed. This pattern maps directly to CWE-639: Authorization Bypass Through User-Controlled Key.
Attack Vector
Exploitation requires network access and a valid, low-privilege Langflow account. No user interaction is required. An attacker enumerates or guesses target flow identifiers and issues API requests referencing them. The attack succeeds against any deployment on affected versions where more than one user account exists. Refer to the IBM Support advisory for vendor-specific details.
Detection Methods for CVE-2026-19294
Indicators of Compromise
- Requests to Langflow flow endpoints referencing flow IDs the authenticated user does not own
- Unexpected execution of flows attributed to users who did not initiate the action
- Spikes in flow-read or flow-run API calls originating from a single authenticated account
- Outbound API calls from downstream integrations that do not correlate with the owning user's activity
Detection Strategies
- Correlate Langflow application logs against the authenticated user ID and the owner ID of the referenced flow, alerting on mismatches
- Deploy web application firewall rules that inspect flow identifier parameters and compare them to session identity
- Baseline per-user flow access patterns and alert on cross-account access anomalies
Monitoring Recommendations
- Enable verbose audit logging on Langflow API endpoints, including flow ID, action, and authenticated principal
- Forward Langflow logs to a centralized SIEM for correlation with identity and network telemetry
- Monitor egress from Langflow workers for unexpected third-party API activity indicating flow execution by unauthorized users
How to Mitigate CVE-2026-19294
Immediate Actions Required
- Upgrade Langflow to a fixed release above 1.11.1 as documented in the IBM Support advisory
- Rotate any API keys, tokens, or credentials embedded in Langflow flows on affected instances
- Audit access logs for cross-user flow access dating back to initial deployment
- Restrict Langflow account provisioning to trusted users until the patch is applied
Patch Information
IBM has published remediation guidance on the IBM Support page. Administrators should apply the vendor-supplied fix for Langflow OSS and validate that flow access enforces owner checks after the upgrade.
Workarounds
- Deploy separate Langflow instances per tenant or trust boundary to eliminate cross-user exposure
- Place Langflow behind an authenticating reverse proxy that enforces per-user path or object scoping
- Disable public account registration and limit users to a small, trusted set until patched
- Remove sensitive credentials from stored flows and inject them at runtime through external secret managers
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
