Vulnerability-Lookup

CVE-2026-34046 (GCVE-0-2026-34046)

Vulnerability from cvelistv5 – Published: 2026-03-27 20:06 – Updated: 2026-04-01 03:55

Title

Langflow: Authenticated Users Can Read, Modify, and Delete Any Flow via Missing Ownership Check

Summary

Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to version 1.5.1, the `_read_flow` helper in `src/backend/base/langflow/api/v1/flows.py` branched on the `AUTO_LOGIN` setting to decide whether to filter by `user_id`. When `AUTO_LOGIN` was `False` (i.e., authentication was enabled), neither branch enforced an ownership check — the query returned any flow matching the given UUID regardless of who owned it. This allowed any authenticated user to read any other user's flow, including embedded plaintext API keys; modify the logic of another user's AI agents, and/or delete flows belonging to other users. The vulnerability was introduced by the conditional logic that was meant to accommodate public/example flows (those with `user_id = NULL`) under auto-login mode, but inadvertently left the authenticated path without an ownership filter. The fix in version 1.5.1 removes the `AUTO_LOGIN` conditional entirely and unconditionally scopes the query to the requesting user.

Severity ?

8.7 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CWE

CWE-639 - Authorization Bypass Through User-Controlled Key
CWE-862 - Missing Authorization

Assigner

GitHub_M

References

URL

Tags

	https://github.com/langflow-ai/langflow/security/…	x_refsource_CONFIRM
	https://github.com/langflow-ai/langflow/pull/8956	x_refsource_MISC

Impacted products

Vendor

Product

Version

langflow-ai

langflow

Affected: < 1.5.1

langflow-ai

langflow-base

Affected: < 0.5.1

Show details on NVD website

JSON

To clipboard

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FKIE_CVE-2026-34046

Vulnerability from fkie_nvd - Published: 2026-03-27 21:17 - Updated: 2026-03-30 13:26

Severity ?

8.7 (High) - CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/langflow-ai/langflow/pull/8956
	security-advisories@github.com	https://github.com/langflow-ai/langflow/security/advisories/GHSA-8c4j-f57c-35cf

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Langflow is a tool for building and deploying AI-powered agents and workflows. Prior to version 1.5.1, the `_read_flow` helper in `src/backend/base/langflow/api/v1/flows.py` branched on the `AUTO_LOGIN` setting to decide whether to filter by `user_id`. When `AUTO_LOGIN` was `False` (i.e., authentication was enabled), neither branch enforced an ownership check \u2014 the query returned any flow matching the given UUID regardless of who owned it. This allowed any authenticated user to read any other user\u0027s flow, including embedded plaintext API keys; modify the logic of another user\u0027s AI agents, and/or delete flows belonging to other users. The vulnerability was introduced by the conditional logic that was meant to accommodate public/example flows (those with `user_id = NULL`) under auto-login mode, but inadvertently left the authenticated path without an ownership filter. The fix in version 1.5.1 removes the `AUTO_LOGIN` conditional entirely and unconditionally scopes the query to the requesting user."
    }
  ],
  "id": "CVE-2026-34046",
  "lastModified": "2026-03-30T13:26:07.647",
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GHSA-8C4J-F57C-35CF

Vulnerability from github – Published: 2026-03-27 19:36 – Updated: 2026-03-27 21:52

Summary

Langflow: Authenticated Users Can Read, Modify, and Delete Any Flow via Missing Ownership Check

Details

Vulnerability

IDOR in `GET/PATCH/DELETE /api/v1/flow/{flow_id}`

The _read_flow helper in src/backend/base/langflow/api/v1/flows.py branched on the AUTO_LOGIN setting to decide whether to filter by user_id. When AUTO_LOGIN was False (i.e., authentication was enabled), neither branch enforced an ownership check — the query returned any flow matching the given UUID regardless of who owned it.

This exposed any authenticated user to:

Read any other user's flow, including embedded plaintext API keys
Modify the logic of another user's AI agents
Delete flows belonging to other users

The vulnerability was introduced by the conditional logic that was meant to accommodate public/example flows (those with user_id = NULL) under auto-login mode, but inadvertently left the authenticated path without an ownership filter.

Fix (PR #8956)

The fix removes the AUTO_LOGIN conditional entirely and unconditionally scopes the query to the requesting user:

-    auth_settings = settings_service.auth_settings
-    stmt = select(Flow).where(Flow.id == flow_id)
-    if auth_settings.AUTO_LOGIN:
-        stmt = stmt.where(
-            (Flow.user_id == user_id) | (Flow.user_id == None)  # noqa: E711
-        )
+    stmt = select(Flow).where(Flow.id == flow_id).where(Flow.user_id == user_id)

All three operations — read, update, and delete — route through _read_flow, so the single change covers the full attack surface. A cross-user isolation test (test_read_flows_user_isolation) was added to prevent regression.

Acknowledgements

Langflow thanks the security researcher who responsibly disclosed this vulnerability:

@chximn-dt

Severity ?

8.7 (High)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 1.5.0"
      },
      "package": {
        "ecosystem": "PyPI",
        "name": "langflow"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
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              "fixed": "1.5.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
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        "last_known_affected_version_range": "\u003c= 0.5.0"
      },
      "package": {
        "ecosystem": "PyPI",
        "name": "langflow-base"
      },
      "ranges": [
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              "introduced": "0"
            },
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              "fixed": "0.5.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-34046"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-639",
      "CWE-862"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-27T19:36:23Z",
    "nvd_published_at": "2026-03-27T21:17:27Z",
    "severity": "HIGH"
  },
  "details": "## Vulnerability\n\n### IDOR in `GET/PATCH/DELETE /api/v1/flow/{flow_id}`\n\nThe `_read_flow` helper in `src/backend/base/langflow/api/v1/flows.py` branched on the `AUTO_LOGIN` setting to decide whether to filter by `user_id`. When `AUTO_LOGIN` was `False` (i.e., authentication was enabled), neither branch enforced an ownership check \u2014 the query returned any flow matching the given UUID regardless of who owned it.\n\nThis exposed any authenticated user to:\n\n- **Read** any other user\u0027s flow, including embedded plaintext API keys\n- **Modify** the logic of another user\u0027s AI agents\n- **Delete** flows belonging to other users\n\nThe vulnerability was introduced by the conditional logic that was meant to accommodate public/example flows (those with `user_id = NULL`) under auto-login mode, but inadvertently left the authenticated path without an ownership filter.\n\n---\n\n## Fix (PR #8956)\n\nThe fix removes the `AUTO_LOGIN` conditional entirely and unconditionally scopes the query to the requesting user:\n\n```diff\n-    auth_settings = settings_service.auth_settings\n-    stmt = select(Flow).where(Flow.id == flow_id)\n-    if auth_settings.AUTO_LOGIN:\n-        stmt = stmt.where(\n-            (Flow.user_id == user_id) | (Flow.user_id == None)  # noqa: E711\n-        )\n+    stmt = select(Flow).where(Flow.id == flow_id).where(Flow.user_id == user_id)\n```\n\nAll three operations \u2014 read, update, and delete \u2014 route through `_read_flow`, so the single change covers the full attack surface. A cross-user isolation test (`test_read_flows_user_isolation`) was added to prevent regression.\n\n---\n\n## Acknowledgements\n\nLangflow thanks the security researcher who responsibly disclosed this vulnerability:\n\n- **[@chximn-dt](https://github.com/chximn-dt)**",
  "id": "GHSA-8c4j-f57c-35cf",
  "modified": "2026-03-27T21:52:39Z",
  "published": "2026-03-27T19:36:23Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/langflow-ai/langflow/security/advisories/GHSA-8c4j-f57c-35cf"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34046"
    },
    {
      "type": "WEB",
      "url": "https://github.com/langflow-ai/langflow/pull/8956"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/langflow-ai/langflow"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Langflow: Authenticated Users Can Read, Modify, and Delete Any Flow via Missing Ownership Check"
}

Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

CVE-2026-34046 (GCVE-0-2026-34046)

FKIE_CVE-2026-34046

GHSA-8C4J-F57C-35CF

Vulnerability

IDOR in GET/PATCH/DELETE /api/v1/flow/{flow_id}

Fix (PR #8956)

Acknowledgements

Tags

Sightings

Nomenclature

IDOR in `GET/PATCH/DELETE /api/v1/flow/{flow_id}`