CVE-2026-58446CWE-306

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

Medium · published June 30, 2026

CVSS v4.0
6.9
EPSS
1%
Percentile
52.8
In the wild
Unconfirmed
What it is

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).

The record
Technical detail
CVSS v4.0
6.9 · MEDIUM
Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
EPSS
0.00703 · 52.8th percentile
Weakness
CWE-306 · Missing Authentication for Critical Function
Published
2026-06-30T21:05Z
EPSS history
Timeline
  • 30 JUN 21:05Z
    Presenton < 0.8.8-beta - Authentication Bypass of Session Auth via Unprotected MCP Endpoint
    cvelistv5