Unrated severityNVD Advisory· Published Jun 30, 2026· Updated Jul 14, 2026
Presenton < 0.8.8-beta - Authentication Bypass of Session Auth via Unprotected MCP Endpoint
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).
Affected products
1Patches
Vulnerability mechanics
References
5- github.com/presenton/presenton/commit/a1103dcef3c761cc8bab44e2862c81a49969abd7mitrepatch
- github.com/presenton/presenton/issues/678mitretechnical-descriptionexploit
- www.vulncheck.com/advisories/presenton-beta-authentication-bypass-of-session-auth-via-unprotected-mcp-endpointmitrethird-party-advisory
- github.com/presenton/presenton/pull/679mitreissue-tracking
- github.com/presenton/presenton/releases/tag/electron-v0.8.8-betamitrerelease-notes
News mentions
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