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Medium · 6.5 CVE-2026-58446 EUVD-2026-40414GHSA-j446-h28c-8p3v

Presenton < 0.8.8-beta - Authentication Bypass of Session Auth via Unprotected MCP Endpoint

Published Jun 30, 2026 · Updated Nov 8, 2026 · Assigned by VulnCheck

Description

Presenton before 0.8.8-beta bundles an MCP server that, on server/Docker deployments configured with session authentication (AUTH_USERNAME/AUTH_PASSWORD), is reachable unauthenticated at /mcp because the nginx front-end does not apply the auth_request gate to that path and the MCP server auto-mints a valid internal session token for the configured user. A remote unauthenticated attacker can invoke MCP tools such as generate_presentation, performing authenticated application actions, consuming the operators configured LLM API keys, and creating presentations in the operators instance. The Electron desktop build is not affected (MCP disabled).

Affected products

VendorProductAffectedFixed
presenton presenton < 0.8.8-beta 0.8.8-beta

References