CVE-2026-34046

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

HIGH
8.8
CVSS Score
Published: March 27, 2026 at 08:06 PM UTC
Updated: June 17, 2026 at 10:38 AM UTC
3 products affected across 2 vendorsLangflowLangflow BaseLangflow

Using langflow by langflow-ai?

Get instant alerts when new vulnerabilities affect langflow - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
HIGH8.8
Exploit prediction
EPSS 0.5%
SSVC
No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.5.1
v < 0.5.1v < 1.5.1
Affected range stops below 0.5.1, so it looks safe — our inference, not a vendor statement
Affected range stops below 1.5.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

x_refsource_CONFIRMPatchVendor Advisory
Source: cverecord
https://github.com/langflow-ai/langflow/security/advisories/GHSA-8c4j-f57c-35cf
x_refsource_MISCIssue TrackingPatch
Source: cverecord
https://github.com/langflow-ai/langflow/pull/8956

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-639CWE-862

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card