CVE-2026-58446
CVE-2026-58446 is a medium-severity vulnerability with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-306.
Key facts
- Severity: Medium (CVSS 3.x base score 6.5)
- CVSS v4: 6.9
- EPSS exploit prediction: 0% (35th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-306
- Published:
- Last modified:
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).
Frequently asked questions
- What is CVE-2026-58446?
- 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).
- How severe is CVE-2026-58446?
- CVE-2026-58446 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability low.
- Is CVE-2026-58446 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (35th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-58446?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- When was CVE-2026-58446 published?
- CVE-2026-58446 was published on 2026-06-30 and last updated on 2026-07-02.
References
- https://github.com/presenton/presenton/commit/a1103dcef3c761cc8bab44e2862c81a49969abd7
- https://github.com/presenton/presenton/issues/678
- https://github.com/presenton/presenton/pull/679
- https://github.com/presenton/presenton/releases/tag/electron-v0.8.8-beta
- https://www.vulncheck.com/advisories/presenton-beta-authentication-bypass-of-session-auth-via-unprotected-mcp-endpoint
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