CVE-2026-58446 (GCVE-0-2026-58446)
Vulnerability from cvelistv5 – Published: 2026-06-30 21:05 – Updated: 2026-11-08 14:07 X_Open Source
VLAI
EPSS
VEX
Title
Presenton < 0.8.8-beta - Authentication Bypass of Session Auth via Unprotected MCP Endpoint
Summary
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).
Severity
6.5 (Medium)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-01 13:58 UTC
CWE
- CWE-306 - Missing Authentication for Critical Function
Assigner
VulnCheck
CNA
References
5 references
| URL | Tags |
|---|---|
| https://github.com/presenton/presenton/releases/t… | release-notes |
| https://github.com/presenton/presenton/issues/678 | technical-descriptionexploitissue-tracking |
| https://github.com/presenton/presenton/pull/679 | issue-trackingpatch |
| https://github.com/presenton/presenton/commit/a11… | patch |
| https://www.vulncheck.com/advisories/presenton-be… | third-party-advisory |
Impacted products
Date Public
2026-06-16 00:00
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