CVE-2026-121139

HIGHCVSS 7.8/10

Last modified

CVE-2026-121139 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. 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.

Description

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.

Metrics

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
Rapid7Metasploit Framework< 6.5.9

References

Timeline

Published
Last Modified
Status
Received

Frequently Asked Questions

What is 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.
How severe is CVE-2026-121139?
CVE-2026-121139 has a CVSS score of 7.8/10 (HIGH severity).
How do I fix CVE-2026-121139?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST