CVE-2026-120816: MongoDB privilege escalation via change stream showSystemEvents

CVE-2026-120816 · Severity: medium · CVSS 4.3 · Published 2026-11-10

MongoDB, a widely-used database platform, allows low-privilege users to bypass access controls on sensitive internal collections through a change stream notification feature. An attacker with basic read permissions can enable an option called showSystemEvents to access restricted data like server-side JavaScript code that often contains credentials, potentially leading to unauthorized access to sensitive information or further system compromise.

Technologies: MongoDB. Vendors: MongoDB.

Quick answers

Is CVE-2026-120816 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-120816 being exploited in the wild.
How severe is CVE-2026-120816?
Medium severity, with a CVSS score of 4.3, published 10 November 2026.
Which products and versions are affected?
MongoDB 7.0.0 through 7.0.47, 8.0.0 through 8.0.36, 8.3.0 through 8.3.15, 9.0.0 through 9.0.6.
Is there a fix for CVE-2026-120816?
Yes: fixed in 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-2026-120816 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-120816?
Check whether you run MongoDB 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: 7.0.48, 8.0.37, 8.3.16, 9.0.7

Technical details

The vulnerability exists in MongoDB's change stream implementation: the privilege check for the showSystemEvents option is based only on the target namespace and does not validate permissions on the affected system collections. A user with find and changeStream privileges on a database or cluster can use showSystemEvents to read events from system.js and other restricted internal collections without requiring direct read access to them. The fix filters changeStream events on system.js when showSystemEvents is used on database- or cluster-scoped streams.

Affected products

  • MongoDB MongoDB 7.0.0 through 7.0.47, 8.0.0 through 8.0.36, 8.3.0 through 8.3.15, 9.0.0 through 9.0.6

Timeline

  • 2026-11-10: disclosed

References

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