CVE-2026-8446Public exploitNetwork attack vectorHinoki check available

Unauthenticated cross-user file disclosure via OAuth fallback

Published Aug 5, 2026 · Updated Aug 5, 2026

Authentication bypass in IBM Langflow OSS 1.0.0 through 1.10.3 allows remote attackers to read cross-user files through MCP. In verify_project_auth, OAuth projects skip the API-key requirement and fall through to a superuser lookup, while the streamable handler omits project ownership validation. The default-enabled MCP Composer and an OAuth-configured target project are required; no authentication or user interaction is needed.

CVSS severity7.5
High
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Authentication bypass in IBM Langflow OSS 1.0.0 through 1.10.3 allows remote attackers to read cross-user files through MCP. In verify_project_auth, OAuth projects skip the API-key requirement and fall through to a superuser lookup, while the streamable handler omits project ownership validation. The default-enabled MCP Composer and an OAuth-configured target project are required; no authentication or user interaction is needed.

The record

CVE
CVE-2026-8446
Published
Aug 5, 2026
Updated
Aug 5, 2026
Vendor
IBM
Product
Langflow OSS
Classifications
CWE-862, CWE-200, CWE-639, CWE-306, CWE-288, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 5, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.0.0 <=1.10.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

IBM · Langflow OSSversion=1.0.0 <=1.10.3

Published CVSS scores

8.6GitHub Security AdvisoryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
7.5IBMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-862Missing Authorization
CWE-200Exposure of Sensitive Information to an Unauthorized Actor
CWE-639Authorization Bypass Through User-Controlled Key
CWE-306Missing Authentication for Critical Function
CWE-288Authentication Bypass Using an Alternate Path or Channel
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo