CVE-2026-17628: IBM Langflow OSS Auth Bypass Vulnerability

CVE-2026-17628 Overview

CVE-2026-17628 is an improper authentication vulnerability [CWE-287] affecting IBM Langflow OSS versions 1.0.0 through 1.10.2. The flaw allows a remote authenticated attacker to change the password of an account without proper authorization checks. This weakness undermines account integrity across Langflow deployments used to build and orchestrate large language model (LLM) workflows.

Critical Impact
An authenticated attacker can modify another user's password, enabling account takeover and unauthorized access to Langflow projects, flows, and connected AI services.

Affected Products

IBM Langflow OSS 1.0.0
IBM Langflow OSS versions 1.0.1 through 1.10.1
IBM Langflow OSS 1.10.2

Discovery Timeline

2026-09-14 - CVE-2026-17628 published to the National Vulnerability Database (NVD)
2026-09-16 - Last updated in NVD database

Technical Details for CVE-2026-17628

Vulnerability Analysis

The vulnerability resides in the password change workflow of IBM Langflow OSS. The application fails to properly verify that the requesting user is authorized to modify the target account's credentials. An authenticated user can therefore submit a password change request that affects an account other than their own.

Exploitation requires network access and valid low-privilege credentials, with no user interaction on the victim side. Successful exploitation compromises the integrity and availability of the affected account without directly leaking data.

Root Cause

The root cause is improper authentication logic in the password reset or change handler. The application does not enforce that the session identity matches the account being modified, nor does it require verification of the current password or a signed reset token bound to the target user.

Attack Vector

An attacker with a valid Langflow account authenticates to the application and issues a password change request targeting another user's account identifier. Because the server-side handler does not validate ownership of the target account, the attacker can overwrite the victim's password. The attacker then authenticates as the victim and accesses the victim's flows, credentials stored in Langflow, and any downstream LLM or data integrations. No verified public proof-of-concept code is available at the time of publication.

Detection Methods for CVE-2026-17628

Indicators of Compromise

Password change events in Langflow application logs where the acting user identifier does not match the target account identifier.
Successful authentications immediately following unexpected password change requests from a different source IP or user agent.
User complaints regarding lockouts or unrecognized password resets on Langflow accounts.

Detection Strategies

Enable verbose audit logging on the Langflow API and correlate POST requests to password change endpoints with the authenticated session identity.
Alert on any password change request where the request body references an account ID that differs from the session owner.
Baseline normal password change frequency per user and flag anomalous spikes or off-hours activity.

Monitoring Recommendations

Forward Langflow web server and application logs to a centralized log platform for retention and correlation.
Monitor authentication events and administrative role changes on Langflow instances exposed to internal or external networks.
Track outbound calls from Langflow to connected LLM providers and data sources for unusual access patterns following suspicious password activity.

How to Mitigate CVE-2026-17628

Immediate Actions Required

Upgrade IBM Langflow OSS to a version later than 1.10.2 as directed by the IBM Security Advisory.
Restrict network exposure of Langflow instances to trusted users and networks until patching is complete.
Force password resets for all Langflow accounts and invalidate active sessions after upgrading.

Patch Information

IBM has published guidance for this vulnerability in the IBM Security Advisory. Administrators should review the advisory for the fixed release version and apply it to all Langflow OSS deployments in the 1.0.0 through 1.10.2 range.

Workarounds

Place Langflow behind an authenticating reverse proxy or VPN to limit access to trusted identities.
Disable or restrict low-privilege account creation until the patched version is deployed.
Review audit logs regularly for anomalous password change activity and revoke suspicious sessions.

bash

# Configuration example: restrict Langflow to localhost and front with an authenticating proxy
export LANGFLOW_HOST=127.0.0.1
export LANGFLOW_PORT=7860
langflow run --host $LANGFLOW_HOST --port $LANGFLOW_PORT