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CVE-2026-33053 — langflow

Fix: langflow-ai/langflow@fdc1b3b

CVE-2026-33053 is a CWE-639 vulnerability in langflow. A fix is available for langflow — see the affected versions and patch details below.

Langflow has Missing Ownership Verification in API Key Deletion (IDOR)

Also known asGHSA-rf6x-r45m-xv3wPYSEC-2026-78
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Oct 31, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-33053.

EPSS Exploitation Probability

via FIRST.org ↗
0.4%probability of exploitation in next 30 days
Lower Risk-0.12%
Lower risk than most CVEs35th percentile — riskier than 35% of all scored CVEsHighest risk
0.00%0.34%0.68%1.02%0.0%0.4%May 26Aug 26Oct 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected
🐍langflow

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Detection Method: Kolega.dev Deep Code Scan

AttributeValue
Locationsrc/backend/base/langflow/api/v1/api_key.py:44-53
Practical ExploitabilityHigh
Developer Approver[email protected]

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.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐍PyPIlangflowall versions1.9.0pip install --upgrade 'langflow==1.9.0'

Affected Products

1 product · 1 configurations
Application
langflowlangflow
< 1.9.0
range

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for langflow, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update langflow to 1.9.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33053 is resolved across your whole dependency graph.

  3. Workarounds

    Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

**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 | [email protected] | ### 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=[D
O3 Security · Impact-Aware SCA

Is CVE-2026-33053 in your dependencies?

Find it across PyPI, including transitive dependencies.

CVE-2026-33053: langflow DoS — Fixed in 1.9.0