Security Digest · Critical advisory (no CVE assigned)
GHSA-vw82-7fv8-r6gp: Obot has an authorization bypass in /mcp-connect/{id} that allows any authenticated user to use any registered MCP server
Summary If you have the MCP Server ID, you can connect to the MCP server even if you don't have permissions to the server.
CVSS 9.6 Critical GitHub-reviewed · critical
Should you act?
- Only if you depend on one of the packages below, directly or transitively, in a vulnerable version. Check your lockfile with
govulncheck ./.... - No CVE has been assigned, so it will not appear in CVE-based scanners that ignore GitHub advisories.
npm audit,pip-auditand Dependabot do read GitHub advisories.
Affected packages
| Ecosystem | Package | Vulnerable | First fixed |
|---|---|---|---|
| Go | github.com/obot-platform/obot | <= 0.21.0 | 0.21.1 |
Details
Summary
If you have the MCP Server ID, you can connect to the MCP server even if you don't have permissions to the server.
The MCP gateway endpoint /mcp-connect/{mcpid} does not enforce Access Control Rules (ACRs). Any authenticated Obot user who possesses an MCP Server ID can connect to that server through the gateway — including making tool calls — regardless of whether they are a member of any MCP Registry that grants access to the server.
In practice this means any User can fully use MCP servers that the administrator believed were restricted to specific groups.
Severity
Reporter estimate: Critical.
| CVSS 3.1 metric | Value | |---|---| | Attack Vector | Network | | Attack Complexity | Low | | Privileges Required | Low (authenticated Obot user, any role ≥ Basic) | | User Interaction | None | | Scope | Changed (Obot authorization bypass enables access to data and operations on an upstream third-party service via Obot's stored OAuth credentials) | | Confidentiality | High | | Integrity | High (many MCP servers expose write tools — e.g. updateEmployee, submitTimeoffRequest, ticket creation, file writes) | | Availability | None | | Vector | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N | | Score | 9.3 / Critical |
The upstream impact depends on which MCP servers are deployed and what scope their stored credentials hold; the bound is "everything the platform's stored OAuth/API credentials can reach."
CVSS: 9.6 (v3.1) CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N
Sources and references
- GitHub Advisory GHSA-vw82-7fv8-r6gp github.com
- github.com github.com
- github.com github.com