TI-2026-26371 Aliases CVE-2026-34046 GHSA-8c4j-f57c-35cf

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

MEDIUM 40CWE-639Published 2026-03-27 · Updated 2026-11-03

Key facts

Attack vector: Network
Privileges required: Low
User interaction: None
Attack complexity: Low
Attack requirements: None
Impact type: Security bypass
Confidentiality · integrity · availability: High · High · High
Fix status: Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-639.

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00477 41st percentileScored 2026-11-07

Fix Fixed langflow (langflow-ai): 1.5.1langflow-base (langflow-ai): 0.5.1+2 more products

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Langflow	langflow	before 1.5.1	1.5.1	Patch available	CNA
Langflow	langflow-base	before 0.5.1	0.5.1	Patch available	CNA
—	langflow (PyPI)	before 1.5.1	1.5.1	Patch available	GHSA-8c4j-f57c-35cf
—	langflow-base (PyPI)	before 0.5.1	0.5.1	Patch available	GHSA-8c4j-f57c-35cf

langflow VendorLangflow Affected before 1.5.1 Fixed in 1.5.1 Patch available CNA
langflow-base VendorLangflow Affected before 0.5.1 Fixed in 0.5.1 Patch available CNA
langflow (PyPI) Vendor— Affected before 1.5.1 Fixed in 1.5.1 Patch available GHSA-8c4j-f57c-35cf
langflow-base (PyPI) Vendor— Affected before 0.5.1 Fixed in 0.5.1 Patch available GHSA-8c4j-f57c-35cf

CPE configurations NVD · 4

CPE	Versions	Role	Vendor
cpe:2.3:a:langflow:langflow::::::::	before 1.5.0	Vulnerable	Langflow
cpe:2.3:a:langflow:langflow:1.5.0:dev0::::::	1.5.0 dev0	Vulnerable	Langflow
cpe:2.3:a:langflow:langflow:1.5.0:dev1::::::	1.5.0 dev1	Vulnerable	Langflow
cpe:2.3:a:langflow:langflow-base::::::python::*	before 0.5.1	Vulnerable	Langflow

cpe:2.3:a:langflow:langflow:*:*:*:*:*:*:*:* Versions before 1.5.0 Vulnerable ·Langflow
cpe:2.3:a:langflow:langflow:1.5.0:dev0:*:*:*:*:*:* Versions 1.5.0 dev0 Vulnerable ·Langflow
cpe:2.3:a:langflow:langflow:1.5.0:dev1:*:*:*:*:*:* Versions 1.5.0 dev1 Vulnerable ·Langflow
cpe:2.3:a:langflow:langflow-base:*:*:*:*:*:python:*:* Versions before 0.5.1 Vulnerable ·Langflow

Remediation

Fix · CNA langflow (langflow-ai) Fixed in 1.5.1
Fix · CNA langflow-base (langflow-ai) Fixed in 0.5.1
Fix · GHSA-8c4j-f57c-35cf langflow (PyPI) Fixed in 1.5.1 Advisory →
Fix · GHSA-8c4j-f57c-35cf langflow-base (PyPI) Fixed in 0.5.1 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-34046
2026-10-03 Alias added: GHSA-8c4j-f57c-35cf
2026-10-25 EPSS moved to the below the 50th percentile
2026-11-03 CISA SSVC decision points changed

References

Patch 2

Advisory 1

https://nvd.nist.gov/vuln/detail/CVE-2026-34046

Other 1

https://github.com/langflow-ai/langflow

TI-2026-08085 Unauthenticated Remote Code Execution via Auto-Login Bypass and Code Validation KEVCVSS 3.1CRITICAL 9.8
TI-2026-00553 Langflow exec_globals Inclusion of Functionality from Untrusted Control Sphere Remote… KEVCVSS 3.0CRITICAL 9.8
TI-2025-24427 Langflow <= 1.6.9 CORS Misconfiguration to Token Hijack & RCE KEVCVSS 4.0CRITICAL 9.4
TI-2025-02845 Langflow < 1.3.0 Unauthenticated RCE via /api/v1/validate/code KEVCVSS 3.1CRITICAL 9.8
TI-2026-25463 Langflow has Unauthenticated Remote Code Execution via Public Flow Build Endpoint KEVCVSS 4.0CRITICAL 9.3
TI-2026-39928 Authorization bypass in langflow KEVCVSS 3.1HIGH 8.4

See all 216 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences