Auth bypass in Rapid7 Metasploit Framework
CVE-2026-121139
The Rapid7 Metasploit msf-ws suffers from a missing authentication vulnerability whereby the REST API grants an unauthenticated "bootstrap" exemption so that the very first administrator can be created when the users table is empty. While the table is empty, POST /api/v1/users is exempt from authentication by design: the route handler calls warden.authenticate!(scope: :admin_api), which resolves to AdminApiToken. The inherited ApiToken#authenticate! short-circuits and returns success!() whenever msf.auth_initialized is false, without ever evaluating AdminApiToken's administrator check. In that state the endpoint creates a user — including an administrator — for an entirely unauthenticated caller. This issue has been fixed in version 6.5.9.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-121139?
- CVE-2026-121139 is a high-severity vulnerability in Rapid7 Metasploit Framework, classified under Missing Authentication for Critical Function. CVSS score: 7.8/10. Published 2026-11-05.
- How severe is CVE-2026-121139?
- High severity. CVSS v3 base score is 7.8 out of 10.