CVE-2026-21445
📋 TL;DR
CVE-2026-21445 is a critical authentication bypass vulnerability in Langflow that allows unauthenticated attackers to access sensitive user conversation data, transaction histories, and perform destructive operations like message deletion. This affects all Langflow deployments prior to version 1.7.0.dev45. Any organization using vulnerable Langflow versions is at risk of data exposure and unauthorized system manipulation.
💻 Affected Systems
- Langflow
📦 What is this software?
Langflow by Langflow
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of all user conversation data, unauthorized deletion of critical messages and workflows, and potential exposure of sensitive business intelligence or personal information stored in Langflow.
Likely Case
Unauthorized access to user conversations and transaction data, potential data theft, and manipulation of AI workflows by malicious actors.
If Mitigated
Proper authentication controls prevent unauthorized access, limiting impact to authenticated users only with appropriate permissions.
🎯 Exploit Status
The vulnerability requires no authentication and involves simple HTTP requests to unprotected endpoints. Attackers can easily craft requests to access or manipulate data.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.7.0.dev45
Vendor Advisory: https://github.com/langflow-ai/langflow/security/advisories/GHSA-c5cp-vx83-jhqx
Restart Required: Yes
Instructions:
1. Update Langflow to version 1.7.0.dev45 or later. 2. Restart the Langflow service. 3. Verify authentication is now required for all sensitive endpoints.
🔧 Temporary Workarounds
Network Access Control
allRestrict network access to Langflow instances using firewalls or network segmentation
Reverse Proxy Authentication
allImplement authentication at the reverse proxy level before requests reach Langflow
🧯 If You Can't Patch
- Isolate Langflow instances behind strict network segmentation with no internet exposure
- Implement web application firewall (WAF) rules to block unauthenticated API requests to sensitive endpoints
🔍 How to Verify
Check if Vulnerable:
Attempt to access sensitive API endpoints without authentication. If endpoints like /api/conversations, /api/transactions, or /api/messages return data without authentication, the system is vulnerable.Check Version:
Check Langflow version in the application interface or via API endpoint /api/versionVerify Fix Applied:
After patching, verify that unauthenticated requests to sensitive endpoints return 401/403 errors instead of data.📡 Detection & Monitoring
Log Indicators:
- Multiple 200/201 responses to sensitive API endpoints from unauthenticated IPs
- Unusual volume of requests to /api/conversations or /api/messages from new IPs
Network Indicators:
- HTTP requests to sensitive Langflow API endpoints without authentication headers
- Unusual data export patterns from Langflow endpoints
SIEM Query:
source="langflow" AND (uri_path="/api/conversations" OR uri_path="/api/messages" OR uri_path="/api/transactions") AND NOT auth_token=* AND response_code=200