CVE-2026-58446
MEDIUMPresenton < 0.8.8-beta - Authentication Bypass of Session Auth via Unprotected MCP Endpoint
Title source: cnaDescription
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 (5)
Core 5
Core References
Release Notes release-notes
Release Notes
https://github.com/presenton/presenton/releases/tag/electron-v0.8.8-beta
Patch patch
Fix Commit
https://github.com/presenton/presenton/commit/a1103dcef3c761cc8bab44e2862c81a49969abd7
Third Party Advisory third-party-advisory
https://www.vulncheck.com/advisories/presenton-beta-authentication-bypass-of-session-auth-via-unprotected-mcp-endpoint
Exploit technical-description
exploit
Researcher Disclosure
https://github.com/presenton/presenton/issues/678
Scores
CVSS v3
6.5
EPSS
0.0044
EPSS Percentile
35.7%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-306
Status
published
Products (1)
presenton/presenton
< 0.8.8-beta
Published
Jun 30, 2026
Tracked Since
Jul 01, 2026