CVE-2026-105699 Langflow: Authenticated Cross-Project File Disclosure via Unscoped MCP Resource Handlers
Authenticated users can access other users' private files and flow artifacts by manipulating resource URIs in MCP connections.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-105699?
CVE-2026-105699 is a high-severity missing authorization vulnerability in langflow-ai langflow, published on 5 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Langflow is a tool for building and deploying AI-powered agents and workflows. From 1.6.8 until 1.9.1, Langflow authenticated access to the project identifier in a project-scoped MCP connection but did not authorize the resource URI supplied to resources/read. read_resource forwarded the attacker-controlled URI to handle_read_resource, which parsed a flow_id and filename and called storage_service.get_file without verifying that the flow belonged to the authenticated user or current project. A user with access to any project-scoped MCP endpoint could therefore request another user's flow-backed file, while global handle_list_resources and handle_list_tools behavior could disclose flow and file identifiers that made targeting easier. The vulnerability disclosed uploaded documents, structured data, prompts, and other private flow artifacts across tenants but did not modify victim files or stored flows. This issue is fixed in version 1.9.1.
Weakness: CWE-639
Which versions are affected by CVE-2026-105699?
3 open source packages ship an affected version, including langflow.
| Package | Affected | Fixed in |
|---|---|---|
langflow PyPI | From 1.6.8 | 1.9.1 |
langflow PyPI | From 1.6.8 | 1.9.1 |
langflow PyPI | From 1.6.8 | 1.9.1 |
How do I fix CVE-2026-105699?
Upgrade langflow to 1.9.1 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-105699 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-105699 exists.
Sources
Also known as GHSA-4hmc-cfm3-w43c, PYSEC-2026-4230.