CVE-2026-58446

medium

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).

References

https://www.vulncheck.com/advisories/presenton-beta-authentication-bypass-of-session-auth-via-unprotected-mcp-endpoint

https://github.com/presenton/presenton/releases/tag/electron-v0.8.8-beta

https://github.com/presenton/presenton/pull/679

https://github.com/presenton/presenton/issues/678

https://github.com/presenton/presenton/commit/a1103dcef3c761cc8bab44e2862c81a49969abd7

Details

Source: Mitre, NVD

Published: 2026-06-30

Updated: 2026-07-01

Risk Information

CVSS v2

Base Score: 6.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:P

Severity: Medium

CVSS v3

Base Score: 6.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L

Severity: Medium

CVSS v4

Base Score: 6.9

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

Severity: Medium

EPSS

EPSS: 0.00437