CVE-2026-58446

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).

References

• https://github.com/presenton/presenton/commit/a1103dcef3c761cc8bab44e2862c81a49969abd7
• https://github.com/presenton/presenton/issues/678
• https://github.com/presenton/presenton/pull/679
• https://github.com/presenton/presenton/releases/tag/electron-v0.8.8-beta
• https://www.vulncheck.com/advisories/presenton-beta-authentication-bypass-of-session-auth-via-unprotected-mcp-endpoint