CVE-2026-33053: Langflow Langflow Is Missing Ownership Verification Vulnerability

HIGH
Advisory Identifier: GHSA-rf6x-r45m-xv3w
CWE-639
Published
Advisory Summary

CVE-2026-33053 is a HIGH langflow is missing ownership verification vulnerability (CWE-639: Authorization Bypass Through User-Controlled Key) affecting Langflow libraries in the PyPI ecosystem. The issue involves langflow is missing ownership verification in api key deletion (idor). Remediation is available by upgrading affected packages to version 1.9.0.

CVE-2026-33053 at a Glance

CVE Identifier CVE-2026-33053
GHSA Identifier GHSA-rf6x-r45m-xv3w
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-639: Authorization Bypass Through User-Controlled Key
Affected Product Langflow
Package Ecosystem PyPI
Published Date
Last Updated

How to Fix CVE-2026-33053

To remediate this vulnerability, upgrade all affected Langflow dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

langflow fixed: 1.9.0
pip install langflow>=1.9.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

pip show langflow

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-33053, inspect your installed packages using pip:

pip show langflow

Analyze the terminal output to locate any version of Langflow in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.9.0), your application is affected.

Note: The pip show langflow command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-639: Authorization Bypass Through User-Controlled Key, where the system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data. In Langflow, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

**Detection Method:** Kolega.dev Deep Code Scan | Attribute | Value | |---|---| | Location | src/backend/base/langflow/api/v1/api_key.py:44-53 | | Practical Exploitability | High | | Developer Approver | faizan@kolega.ai | ### Description The delete_api_key_route() endpoint accepts an api_key_id path parameter and deletes it with only a generic authentication check (get_current_active_user dependency). However, the delete_api_key() CRUD function does NOT verify that the API key belongs to the current user before deletion. ### Affected Code ``` @router.delete("/{api_key_id}", dependencies=[Depends(auth_utils.get_current_active_user)]) async def delete_api_key_route( api_key_id: UUID, db: DbSession, ): try: await delete_api_key(db, api_key_id) except Exception as e: raise HTTPException(status_code=400, detail=str(e)) from e return {"detail": "API Key deleted"} ``` ### Evidence In crud.py lines 44-49, delete_api_key() retrieves the API key by ID and deletes it without checking if the key belongs to the authenticated user. The endpoint also doesn't pass the current_user to the delete function for verification. ### Impact An authenticated attacker can enumerate and delete API keys belonging to other users by guessing or discovering their API key IDs. This allows account takeover, denial of service, and disruption of other users' integrations. ### Recommendation Modify the delete_api_key endpoint and function: (1) Pass current_user to the delete function; (2) In delete_api_key(), verify api_key.user_id == current_user.id before deletion; (3) Raise a 403 Forbidden error if the user doesn't own the key. Example: if api_key.user_id != user_id: raise HTTPException(status_code=403, detail='Unauthorized') ### Notes Confirmed IDOR vulnerability. The delete_api_key_route endpoint at line 44-53 accepts an api_key_id and calls delete_api_key(db, api_key_id) without passing the current_user. The CRUD function delete_api_key() at crud.py:44-49 retrieves the API key by ID and deletes it without verifying ownership (api_key.user_id == current_user.id). Compare this to the GET endpoint at lines 17-28 which correctly filters by user_id, and the POST endpoint at lines 31-41 which correctly associates the key with user_id. An authenticated attacker can delete any user's API keys by guessing/enumerating UUIDs. Fix: Pass current_user to delete_api_key and verify api_key.user_id == current_user.id before deletion, returning 403 if unauthorized. ### Developer Review Notes Does not accept current_user as a parameter. Allowing deletion of any user's API keys even without permissions.

CVE-2026-33053 Affected Langflow Versions

1 component(s)
Fixed Versions:
1.9.0
Product / Package Ecosystem Affected Versions Fixed Version
langflow
PyPI
< 1.9.0
1.9.0

References

Frequently Asked Questions

What is CVE-2026-33053?
CVE-2026-33053 is a security vulnerability in Langflow involving Langflow is Missing Ownership Verification in API Key Deletion (IDOR) under CWE-639: Authorization Bypass Through User-Controlled Key.
Which Langflow versions are affected?
Affected versions include releases prior to 1.9.0 across affected packages: langflow.
What version fixes CVE-2026-33053?
Upgrading to 1.9.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is langflow affected?
Yes, langflow is affected in releases prior to 1.9.0. Upgrade your dependency to 1.9.0 or later.
What CWE is associated with CVE-2026-33053?
CVE-2026-33053 is classified under CWE-639: Authorization Bypass Through User-Controlled Key (The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.).
How can I check PyPI dependencies for CVE-2026-33053?
Run the dependency tree command: 'pip show langflow'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-rf6x-r45m-xv3w",
  "modified" : "2026-06-06T00:55:19Z",
  "published" : "2026-03-18T12:58:35Z",
  "aliases" : [ "CVE-2026-33053" ],
  "summary" : "Langflow is Missing Ownership Verification in API Key Deletion (IDOR)",
  "details" : "**Detection Method:** Kolega.dev Deep Code Scan\n\n| Attribute | Value |\n|---|---|\n| Location | src/backend/base/langflow/api/v1/api_key.py:44-53 |\n| Practical Exploitability | High |\n| Developer Approver | faizan@kolega.ai |\n\n### Description\nThe delete_api_key_route() endpoint accepts an api_key_id path parameter and deletes it with only a generic authentication check (get_current_active_user dependency). However, the delete_api_key() CRUD function does NOT verify that the API key belongs to the current user before deletion.\n\n### Affected Code\n```\n@router.delete(\"/{api_key_id}\", dependencies=[Depends(auth_utils.get_current_active_user)])\nasync def delete_api_key_route(\n    api_key_id: UUID,\n    db: DbSession,\n):\n    try:\n        await delete_api_key(db, api_key_id)\n    except Exception as e:\n        raise HTTPException(status_code=400, detail=str(e)) from e\n    return {\"detail\": \"API Key deleted\"}\n```\n\n### Evidence\nIn crud.py lines 44-49, delete_api_key() retrieves the API key by ID and deletes it without checking if the key belongs to the authenticated user. The endpoint also doesn't pass the current_user to the delete function for verification.\n\n### Impact\nAn authenticated attacker can enumerate and delete API keys belonging to other users by guessing or discovering their API key IDs. This allows account takeover, denial of service, and disruption of other users' integrations.\n\n### Recommendation\nModify the delete_api_key endpoint and function: (1) Pass current_user to the delete function; (2) In delete_api_key(), verify api_key.user_id == current_user.id before deletion; (3) Raise a 403 Forbidden error if the user doesn't own the key. Example: if api_key.user_id != user_id: raise HTTPException(status_code=403, detail='Unauthorized')\n\n### Notes\nConfirmed IDOR vulnerability. The delete_api_key_route endpoint at line 44-53 accepts an api_key_id and calls delete_api_key(db, api_key_id) without passing the current_user. The CRUD function delete_api_key() at crud.py:44-49 retrieves the API key by ID and deletes it without verifying ownership (api_key.user_id == current_user.id). Compare this to the GET endpoint at lines 17-28 which correctly filters by user_id, and the POST endpoint at lines 31-41 which correctly associates the key with user_id. An authenticated attacker can delete any user's API keys by guessing/enumerating UUIDs. Fix: Pass current_user to delete_api_key and verify api_key.user_id == current_user.id before deletion, returning 403 if unauthorized.\n\n### Developer Review Notes\nDoes not accept current_user as a parameter. Allowing deletion of any user's API keys even without permissions.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "langflow"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.9.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/langflow-ai/langflow/security/advisories/GHSA-rf6x-r45m-xv3w"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/langflow-ai/langflow/commit/fdc1b3b1448ff3317d73d3e769a6c4a1717f74d7"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/langflow-ai/langflow"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/langflow-ai/langflow/releases/tag/1.7.2"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/langflow/PYSEC-2026-78.yaml"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-639" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-18T12:58:35Z",
    "nvd_published_at" : "2026-03-20T07:16:13Z"
  }
}