LangflowApplication

CVE-2026-7664

CRITICAL · 9.8 CVSS v3.1 Published 2026-06-22
Fix available
A fix is available. Upgrade to after 1.8.4 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
IBM Langflow OSS 1.0.0 through 1.8.4 could allow unauthenticated attackers to access protected MCP project resources and execute MCP operations due to improper authorization enforcement in the Streamable MCP transport endpoint.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

IBM Langflow OSS versions 1.0.0 through 1.8.4 contain an improper authorization vulnerability in the Streamable MCP transport endpoint that allows unauthenticated attackers to bypass authentication and directly access protected MCP project resources, enabling execution of arbitrary MCP operations.

MitigationUpgrade to IBM Langflow OSS version beyond 1.8.4 that includes proper authorization enforcement, or implement explicit authentication and authorization checks on all Streamable MCP transport endpoint requests.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
LangflowApplication
Affected:>= 1.0.0, <= 1.8.4

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Langflow installation and version
    Check the installed Langflow version by running 'pip show langflow' or checking the package version in your environment
    Affected if Version is 1.0.0 through 1.8.4 inclusive
  2. Confirm Streamable MCP transport is enabled
    Examine Langflow configuration files or environment settings for Streamable MCP transport module settings
    Affected if Streamable MCP transport endpoint is enabled or exposed in the configuration
  3. Test endpoint accessibility without authentication
    Send an HTTP request to the Streamable MCP transport endpoint (typically /api/v1/mcp/streamable or similar path) without providing any authentication credentials
    Affected if The endpoint returns successful data or accepts operations without requiring authentication
  4. Inspect authorization configuration for MCP endpoint
    Review Langflow's authorization configuration or middleware settings related to the MCP transport endpoint
    Affected if No authorization middleware or access control is configured for the Streamable MCP endpoint

A system is affected if it runs Langflow version 1.0.0-1.8.4 and has the Streamable MCP transport endpoint enabled with missing or insufficient authorization checks allowing unauthenticated access.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 1.8.4
Interim mitigation

Upgrade to IBM Langflow OSS version beyond 1.8.4 that includes proper authorization enforcement, or implement explicit authentication and authorization checks on all Streamable MCP transport endpoint requests.

Recommended fix Moderate confidence

Langflow 1.8.5 or later

  1. 1. Backup your current Langflow installation and database
  2. 2. Stop the Langflow service
  3. 3. Upgrade Langflow to version 1.8.5 or later using your package manager (e.g., pip install langflow>=1.8.5)
  4. 4. Verify the upgrade was successful by checking the installed version
  5. 5. Restart the Langflow service
  6. 6. Test that authentication is properly enforced on MCP endpoints
Caveat Review release notes for any breaking changes between 1.0.0-1.8.4 and 1.8.5+

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Langflow Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA3.0 h
19.0 hours of engineering $3,380
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,408.

Scan for this in your stack

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dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-7664 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data