id: PYSEC-2026-2567
published: "2026-07-13T14:36:45.466607Z"
modified: "2026-07-13T16:04:31.926847Z"
aliases:
- CVE-2026-34046
- GHSA-8c4j-f57c-35cf
summary: "Langflow: Authenticated Users Can Read, Modify, and Delete Any Flow via Missing Ownership Check"
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 — 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's flow, including embedded plaintext API keys\n- **Modify** the logic of another user's 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 — 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.\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)**"
affected:
- package:
    name: langflow
    ecosystem: PyPI
    purl: pkg:pypi/langflow
  ranges:
  - type: ECOSYSTEM
    events:
    - introduced: "0"
    - fixed: 1.5.1
  versions:
  - 0.0.31
  - 0.0.32
  - 0.0.33
  - 0.0.40
  - 0.0.44
  - 0.0.45
  - 0.0.46
  - 0.0.52
  - 0.0.53
  - 0.0.54
  - 0.0.55
  - 0.0.56
  - 0.0.57
  - 0.0.58
  - 0.0.61
  - 0.0.62
  - 0.0.63
  - 0.0.64
  - 0.0.65
  - 0.0.66
  - 0.0.67
  - 0.0.68
  - 0.0.69
  - 0.0.70
  - 0.0.71
  - 0.0.72
  - 0.0.73
  - 0.0.74
  - 0.0.75
  - 0.0.76
  - 0.0.78
  - 0.0.79
  - 0.0.80
  - 0.0.81
  - 0.0.83
  - 0.0.84
  - 0.0.85
  - 0.0.86
  - 0.0.87
  - 0.0.88
  - 0.0.89
  - 0.1.0
  - 0.1.2
  - 0.1.3
  - 0.1.4
  - 0.1.5
  - 0.1.6
  - 0.1.7
  - 0.2.0
  - 0.2.1
  - 0.2.10
  - 0.2.11
  - 0.2.12
  - 0.2.13
  - 0.2.2
  - 0.2.3
  - 0.2.4
  - 0.2.5
  - 0.2.6
  - 0.2.7
  - 0.2.8
  - 0.2.9
  - 0.3.0
  - 0.3.1
  - 0.3.2
  - 0.3.3
  - 0.3.4
  - 0.4.0
  - 0.4.1
  - 0.4.10
  - 0.4.11
  - 0.4.12
  - 0.4.14
  - 0.4.15
  - 0.4.16
  - 0.4.17
  - 0.4.18
  - 0.4.19
  - 0.4.2
  - 0.4.20
  - 0.4.21
  - 0.4.3
  - 0.4.4
  - 0.4.5
  - 0.4.6
  - 0.4.7
  - 0.4.8
  - 0.4.9
  - 0.5.0
  - 0.5.0a0
  - 0.5.0a1
  - 0.5.0a2
  - 0.5.0a3
  - 0.5.0a4
  - 0.5.0a5
  - 0.5.0a6
  - 0.5.0b0
  - 0.5.0b2
  - 0.5.0b3
  - 0.5.0b4
  - 0.5.0b5
  - 0.5.0b6
  - 0.5.1
  - 0.5.10
  - 0.5.11
  - 0.5.12
  - 0.5.2
  - 0.5.3
  - 0.5.4
  - 0.5.5
  - 0.5.6
  - 0.5.7
  - 0.5.8
  - 0.5.9
  - 0.6.0
  - 0.6.0rc1
  - 0.6.1
  - 0.6.10
  - 0.6.11
  - 0.6.12
  - 0.6.14
  - 0.6.15
  - 0.6.16
  - 0.6.17
  - 0.6.18
  - 0.6.19
  - 0.6.2
  - 0.6.3
  - 0.6.3a0
  - 0.6.3a1
  - 0.6.3a2
  - 0.6.3a3
  - 0.6.3a4
  - 0.6.3a5
  - 0.6.3a6
  - 0.6.3a7
  - 0.6.4
  - 0.6.4a0
  - 0.6.4a1
  - 0.6.5
  - 0.6.5a0
  - 0.6.5a1
  - 0.6.5a10
  - 0.6.5a11
  - 0.6.5a12
  - 0.6.5a13
  - 0.6.5a2
  - 0.6.5a3
  - 0.6.5a4
  - 0.6.5a5
  - 0.6.5a6
  - 0.6.5a7
  - 0.6.5a8
  - 0.6.5a9
  - 0.6.6
  - 0.6.7
  - 0.6.7a1
  - 0.6.7a2
  - 0.6.7a3
  - 0.6.7a5
  - 0.6.8
  - 0.6.9
  - 1.0.0
  - 1.0.0a0
  - 1.0.0a1
  - 1.0.0a10
  - 1.0.0a11
  - 1.0.0a12
  - 1.0.0a13
  - 1.0.0a14
  - 1.0.0a15
  - 1.0.0a17
  - 1.0.0a18
  - 1.0.0a19
  - 1.0.0a2
  - 1.0.0a20
  - 1.0.0a21
  - 1.0.0a22
  - 1.0.0a23
  - 1.0.0a24
  - 1.0.0a25
  - 1.0.0a26
  - 1.0.0a27
  - 1.0.0a28
  - 1.0.0a29
  - 1.0.0a3
  - 1.0.0a30
  - 1.0.0a31
  - 1.0.0a32
  - 1.0.0a33
  - 1.0.0a34
  - 1.0.0a35
  - 1.0.0a36
  - 1.0.0a37
  - 1.0.0a38
  - 1.0.0a39
  - 1.0.0a4
  - 1.0.0a40
  - 1.0.0a41
  - 1.0.0a42
  - 1.0.0a43
  - 1.0.0a44
  - 1.0.0a45
  - 1.0.0a46
  - 1.0.0a47
  - 1.0.0a48
  - 1.0.0a49
  - 1.0.0a5
  - 1.0.0a50
  - 1.0.0a51
  - 1.0.0a52
  - 1.0.0a53
  - 1.0.0a55
  - 1.0.0a56
  - 1.0.0a57
  - 1.0.0a58
  - 1.0.0a59
  - 1.0.0a6
  - 1.0.0a60
  - 1.0.0a61
  - 1.0.0a7
  - 1.0.0a8
  - 1.0.0a9
  - 1.0.0rc0
  - 1.0.0rc1
  - 1.0.1
  - 1.0.10
  - 1.0.11
  - 1.0.12
  - 1.0.13
  - 1.0.14
  - 1.0.15
  - 1.0.16
  - 1.0.17
  - 1.0.18
  - 1.0.19
  - 1.0.19.post1
  - 1.0.19.post2
  - 1.0.2
  - 1.0.3
  - 1.0.4
  - 1.0.5
  - 1.0.6
  - 1.0.7
  - 1.0.8
  - 1.0.9
  - 1.1.0
  - 1.1.1
  - 1.1.2
  - 1.1.3
  - 1.1.4
  - 1.1.4.post1
  - 1.2.0
  - 1.3.0
  - 1.3.1
  - 1.3.2
  - 1.3.3
  - 1.3.4
  - 1.4.0
  - 1.4.1
  - 1.4.2
  - 1.4.3
  - 1.5.0
  - 1.5.0.post1
  - 1.5.0.post2
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
- type: PACKAGE
  url: https://pypi.org/project/langflow
- type: ADVISORY
  url: https://github.com/advisories/GHSA-8c4j-f57c-35cf
severity:
- type: CVSS_V4
  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