Is CVE-2026-120815 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-120815 being exploited in the wild.

How severe is CVE-2026-120815?

High severity, with a CVSS score of 8.4, published 10 November 2026.

Which products and versions are affected?

MongoDB Server before 7.0.48, before 8.0.37, before 8.3.16, before 9.0.7.

Is there a fix for CVE-2026-120815?

Yes: fixed in MongoDB Server 7.0.48, 8.0.37, 8.3.16, 9.0.7. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-120815 attacked?

It is attacked with local access, in a hosted service.

Am I affected by CVE-2026-120815?

Check whether you run MongoDB Server at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-120815: MongoDB Server authorization bypass via localhost exception

CVE-2026-120815 · Severity: high · CVSS 8.4 · Published 2026-11-10

MongoDB Server with authorization enabled contains a flaw in how it manages the localhost exception, a feature that permits unauthenticated local connections during initial setup. An attacker with local host access can bypass authorization checks if the first user is created in the $external database, allowing them to create administrative accounts and gain full control of the database and its data.

Technologies: MongoDB Server. Vendors: MongoDB.

Quick answers

Is CVE-2026-120815 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-120815 being exploited in the wild.
How severe is CVE-2026-120815?: High severity, with a CVSS score of 8.4, published 10 November 2026.
Which products and versions are affected?: MongoDB Server before 7.0.48, before 8.0.37, before 8.3.16, before 9.0.7.
Is there a fix for CVE-2026-120815?: Yes: fixed in MongoDB Server 7.0.48, 8.0.37, 8.3.16, 9.0.7. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-120815 attacked?: It is attacked with local access, in a hosted service.
Am I affected by CVE-2026-120815?: Check whether you run MongoDB Server at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Fixed in: MongoDB Server 7.0.48, 8.0.37, 8.3.16, 9.0.7

Technical details

An incorrect authorization check in AuthorizationSessionImpl::_getDefaultPrivileges fails to close the localhost exception after a user is created in the $external database, unlike the expected behavior when a user is created in the admin database. An unauthenticated local attacker can exploit this to run privileged createUser commands and obtain root access to the server.

Affected products

MongoDB Server before 7.0.48, before 8.0.37, before 8.3.16, before 9.0.7

Timeline

2026-11-10: disclosed: CVE-2026-120815 published

References

https://jira.mongodb.org/browse/SERVER-134872

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