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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
2026-06-22
Advisory published
2026-06-12
Advisory updated
2026-06-22

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.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-11933 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-11933

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-11933 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-11933

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.