PT-2026-59228 · Pypi · Langflow-Base

Published

2026-07-13

·

Updated

2026-07-13

CVSS v4.0

8.8

High

VectorAV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:P

Summary

Multiple critical API endpoints in Langflow are missing authentication controls, allowing any unauthenticated user to access sensitive user conversation data, transaction histories, and perform destructive operations including message deletion. This affects endpoints handling personal data and system operations that should require proper authorization.

Details

The vulnerability exists in three API endpoints within src/backend/base/langflow/api/v1/monitor.py that are missing the required dependencies=[Depends(get current active user)] authentication dependency:
Affected Endpoints:
  1. GET /api/v1/monitor/messages (Line 61)
python
@router.get("/messages") # ❌ Missing authentication
async def get messages(
  session: DbSession,
  flow id: Annotated[UUID | None, Query()] = None,
  session id: Annotated[str | None, Query()] = None,
  # ... other parameters
) -> list[MessageResponse]:
  1. GET /api/v1/monitor/transactions (Line 183)
python
@router.get("/transactions") # ❌ Missing authentication
async def get transactions(
  flow id: Annotated[UUID, Query()],
  session: DbSession,
  params: Annotated[Params | None, Depends(custom params)],
) -> Page[TransactionTable]:
  1. DELETE /api/v1/monitor/messages/session/{session id} (Line 165)
python
@router.delete("/messages/session/{session id}", status code=204) # ❌ Missing authentication
async def delete messages session(
  session id: str,
  session: DbSession,
):
Inconsistency Evidence: Other endpoints in the same file properly implement authentication:
python
@router.get("/messages/sessions", dependencies=[Depends(get current active user)]) # ✅ Properly secured
@router.delete("/messages", status code=204, dependencies=[Depends(get current active user)]) # ✅ Properly secured

PoC

Complete reproduction steps to demonstrate the vulnerability:
Prerequisites:
  1. Start a Langflow server instance
  2. Ensure no authentication headers or API keys are provided
Reproduction Commands:
bash
# 1. Access all user conversations without authentication
curl http://localhost:7860/api/v1/monitor/messages

# 2. Access transaction history without authentication
curl "http://localhost:7860/api/v1/monitor/transactions?flow id=00000000-0000-0000-0000-000000000000"

# 3. Delete user messages by session without authentication
curl -X DELETE http://localhost:7860/api/v1/monitor/messages/session/00000000-0000-0000-0000-000000000000
Expected vs Actual Behavior:
  • Expected: All requests should return 401 Unauthorized
  • Actual: All requests return successful responses with sensitive data or perform destructive operations

Impact

Vulnerability Type: Broken Authentication and Authorization (OWASP Top 10 - A01:2021)
Severity: High
Who is Impacted:
  • All Langflow users: Personal conversation data exposed to unauthorized access
  • System administrators: Transaction logs disclosed
Specific Impacts:
  1. Data Breach: Unauthorized access to user conversations containing potentially sensitive personal information
  2. Privacy Violation: Transaction histories and user activity patterns exposed without consent
  3. Data Destruction: Malicious actors can delete user conversation histories without authorization
  4. Compliance Risk: Potential violations of data protection regulations (GDPR, CCPA, etc.)
  5. System Intelligence: Attackers can gather information about system usage patterns and user behavior
Attack Scenarios:
  • Malicious users accessing proprietary conversation data
  • Malicious users deleting other users' conversation histories
  • Automated scraping of all user conversations for data harvesting
  • Reconnaissance attacks to understand system architecture and usage patterns
Recommended Fix: Add authentication dependencies to all affected endpoints:
python
@router.get("/messages", dependencies=[Depends(get current active user)])
@router.get("/transactions", dependencies=[Depends(get current active user)])
@router.delete("/messages/session/{session id}", dependencies=[Depends(get current active user)])
Environment:
  • Langflow Version: Current main branch
  • Affected Components: API v1 monitoring endpoints
  • Authentication System: FastAPI dependency injection with get current active user
25-090901

Fix

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dbugs@ptsecurity.com

Related Identifiers

PYSEC-2026-2571

Affected Products

Langflow-Base