PatchSiren cyber security CVE debrief

CVE-2026-11933 MongoDB CVE debrief

CVE-2026-11933 is a use-after-free vulnerability in MongoDB Server's server-side JavaScript engine. An authenticated user with read privileges who can run server-side JavaScript can cause the server to access memory that has already been freed, potentially resulting in disclosure of information from the mongod process memory or a denial of service through a server crash.

Vendor: MongoDB
Product: Unknown
CVSS: HIGH 8.7
CISA KEV: Not listed in stored evidence
Original CVE published: 2026-06-12
Original CVE updated: 2026-06-12
Advisory published: 2026-06-12
Advisory updated: 2026-06-12

Who should care

Users of MongoDB Server who have server-side JavaScript enabled, particularly those with authenticated users who have read privileges.

Technical summary

The vulnerability exists in the server-side JavaScript engine when converting BSON documents to JavaScript arrays. An authenticated user with read privileges who can run server-side JavaScript (for example, via $where or $function) can exploit this vulnerability.

Defensive priority

High

Recommended defensive actions

Apply the patch or update provided by MongoDB to fix the use-after-free vulnerability.
Restrict access to server-side JavaScript execution to only necessary users and roles.
Monitor MongoDB Server logs for suspicious activity.

Evidence notes

The CVE record and NVD detail pages provide information on the vulnerability, including its CVSS score and weaknesses.

Official resources

CVE-2026-11933 was published on 2026-06-12T02:16:38.527Z and modified on 2026-06-12T16:06:17.027Z.