CVE-2026-58446 Presenton < 0.8.8-beta - Authentication Bypass of Session Auth via Unprotected MCP Endpoint
Unauthenticated attackers can bypass session authentication on the MCP endpoint to perform authenticated actions and consume API keys in server deployments.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-58446?
CVE-2026-58446 is a medium-severity authentication bypass vulnerability in presenton, published on 30 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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).
Weakness: CWE-306
Which versions are affected by CVE-2026-58446?
How do I fix CVE-2026-58446?
No fix has been published for CVE-2026-58446 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-58446 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-58446 exists.
Sources
Also known as GHSA-j446-h28c-8p3v.