CVE-2026-58446 MEDIUM

CVE-2026-58446: Presenton < 0.8.8-beta - Authentication Bypass of Session Auth via Unprotected MCP Endpoint

Vendor Presenton
Product presenton
Weakness CWE-306 · Missing auth
Published June 30, 2026
Last update June 30, 2026

CVSS base score

6.5/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L

What the vulnerability does

01Description

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).

Key dates

02Disclosure timeline

June 30, 2026 CVE published