ghsa-c5cp-vx83-jhqx
Vulnerability from github
Published
2026-01-02 21:11
Modified
2026-01-03 00:32
Severity ?
8.8 (High) - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:P
Summary
Langflow Missing Authentication on Critical API Endpoints
Details

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]:

  2. 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]:

  3. 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

Show details on source website

To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "langflow-base"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.5.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-21445"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-306"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-01-02T21:11:50Z",
    "nvd_published_at": "2026-01-02T20:16:17Z",
    "severity": "HIGH"
  },
  "details": "### Summary\nMultiple 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.\n\n### Details\nThe 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:\n\n**Affected Endpoints:**\n\n1. **GET `/api/v1/monitor/messages`** (Line 61)\n   ```python\n   @router.get(\"/messages\")  # \u274c Missing authentication\n   async def get_messages(\n       session: DbSession,\n       flow_id: Annotated[UUID | None, Query()] = None,\n       session_id: Annotated[str | None, Query()] = None,\n       # ... other parameters\n   ) -\u003e list[MessageResponse]:\n   ```\n\n2. **GET `/api/v1/monitor/transactions`** (Line 183)\n   ```python\n   @router.get(\"/transactions\")  # \u274c Missing authentication\n   async def get_transactions(\n       flow_id: Annotated[UUID, Query()],\n       session: DbSession,\n       params: Annotated[Params | None, Depends(custom_params)],\n   ) -\u003e Page[TransactionTable]:\n   ```\n\n3. **DELETE `/api/v1/monitor/messages/session/{session_id}`** (Line 165)\n   ```python\n   @router.delete(\"/messages/session/{session_id}\", status_code=204)  # \u274c Missing authentication\n   async def delete_messages_session(\n       session_id: str,\n       session: DbSession,\n   ):\n   ```\n\n**Inconsistency Evidence:**\nOther endpoints in the same file properly implement authentication:\n```python\n@router.get(\"/messages/sessions\", dependencies=[Depends(get_current_active_user)])  # \u2705 Properly secured\n@router.delete(\"/messages\", status_code=204, dependencies=[Depends(get_current_active_user)])  # \u2705 Properly secured\n```\n\n### PoC\nComplete reproduction steps to demonstrate the vulnerability:\n\n**Prerequisites:**\n1. Start a Langflow server instance\n2. Ensure no authentication headers or API keys are provided\n\n**Reproduction Commands:**\n```bash\n# 1. Access all user conversations without authentication\ncurl http://localhost:7860/api/v1/monitor/messages\n\n# 2. Access transaction history without authentication\ncurl \"http://localhost:7860/api/v1/monitor/transactions?flow_id=00000000-0000-0000-0000-000000000000\"\n\n# 3. Delete user messages by session without authentication\ncurl -X DELETE http://localhost:7860/api/v1/monitor/messages/session/00000000-0000-0000-0000-000000000000\n```\n\n**Expected vs Actual Behavior:**\n- **Expected:** All requests should return `401 Unauthorized` \n- **Actual:** All requests return successful responses with sensitive data or perform destructive operations\n\n### Impact\n\n**Vulnerability Type:** Broken Authentication and Authorization (OWASP Top 10 - A01:2021)\n\n**Severity:** High\n\n**Who is Impacted:**\n- **All Langflow users**: Personal conversation data exposed to unauthorized access\n- **System administrators**: Transaction logs disclosed\n\n**Specific Impacts:**\n1. **Data Breach**: Unauthorized access to user conversations containing potentially sensitive personal information\n2. **Privacy Violation**: Transaction histories and user activity patterns exposed without consent\n3. **Data Destruction**: Malicious actors can delete user conversation histories without authorization\n4. **Compliance Risk**: Potential violations of data protection regulations (GDPR, CCPA, etc.)\n5. **System Intelligence**: Attackers can gather information about system usage patterns and user behavior\n\n**Attack Scenarios:**\n- Malicious users accessing proprietary conversation data\n- Malicious users deleting other users\u0027 conversation histories\n- Automated scraping of all user conversations for data harvesting\n- Reconnaissance attacks to understand system architecture and usage patterns\n\n**Recommended Fix:**\nAdd authentication dependencies to all affected endpoints:\n\n```python\n@router.get(\"/messages\", dependencies=[Depends(get_current_active_user)])\n@router.get(\"/transactions\", dependencies=[Depends(get_current_active_user)])\n@router.delete(\"/messages/session/{session_id}\", dependencies=[Depends(get_current_active_user)])\n```\n\n**Environment:**\n- Langflow Version: Current main branch\n- Affected Components: API v1 monitoring endpoints\n- Authentication System: FastAPI dependency injection with `get_current_active_user`\n\n\u003cimg width=\"1908\" height=\"1029\" alt=\"25-090901\" src=\"https://github.com/user-attachments/assets/44bd03b4-6ada-45b7-b81b-9cb83747172b\" /\u003e",
  "id": "GHSA-c5cp-vx83-jhqx",
  "modified": "2026-01-03T00:32:20Z",
  "published": "2026-01-02T21:11:50Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/langflow-ai/langflow/security/advisories/GHSA-c5cp-vx83-jhqx"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-21445"
    },
    {
      "type": "WEB",
      "url": "https://github.com/langflow-ai/langflow/commit/3fed9fe1b5658f2c8656dbd73508e113a96e486a"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/langflow-ai/langflow"
    },
    {
      "type": "WEB",
      "url": "https://github.com/langflow-ai/langflow/releases/tag/1.5.1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:P",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Langflow Missing Authentication on Critical API Endpoints"
}


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