# CVE-2026-93764: Mongoid client-side encryption omission in embedded models

Source: https://junglewise.ai/threats/cve-2026-93764-mongoid-may-omit-encryption-rules-for-fields-declared-on-embedded  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-18. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-93764 · Severity: medium · CVSS 6.5 · Published 2026-09-18

Mongoid, a MongoDB object mapper library, may fail to apply encryption rules to fields declared in embedded data models when setting up client-side field-level encryption. This can cause sensitive data that was meant to be encrypted to be stored in readable form in the database or backups. Database administrators or anyone with read access to the underlying data files could view information that should have been protected.

Technologies: [MongoDB Mongoid](https://junglewise.ai/threats/technologies/mongoid). Vendors: [MongoDB](https://junglewise.ai/threats/vendors/mongodb).

## Quick answers

**Is CVE-2026-93764 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-93764 being exploited in the wild.

**How severe is CVE-2026-93764?** Medium severity, with a CVSS score of 6.5, published 18 September 2026.

**Which products and versions are affected?** MongoDB Mongoid.

**Is there a fix for CVE-2026-93764?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-93764 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-93764?** Check whether you run MongoDB Mongoid. 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.

## Technical details

Mongoid omits encryption rules for fields on embedded models when generating the client-side field-level encryption (CSFLE) schema, allowing plaintext storage of encrypted-intended data. The vulnerability affects applications that explicitly enable CSFLE, with no error or warning to alert users of the misconfiguration. An attacker with database read access, backup access, or file-level access to underlying data stores can retrieve unencrypted sensitive data.

## Affected products

- MongoDB Mongoid

## Timeline

- 2026-09-18: disclosed

## References

- [https://jira.mongodb.org/browse/MONGOID-5989](https://jira.mongodb.org/browse/MONGOID-5989)

## Related threats

- [Mongoid unsafe reflection weakness in query path for embedded documents](https://junglewise.ai/threats/cve-2026-93762-mongoid-contains-an-unsafe-reflection-weakness-in-the-query-path)
- [Mongoid inefficient regex complexity in query evaluation](https://junglewise.ai/threats/cve-2026-93761-an-inefficient-regular-expression-complexity-issue-in-the-in)
- [Mongoid query operator injection via unsanitized filter parameters](https://junglewise.ai/threats/cve-2026-93760-mongoid-does-not-restrict-which-query-operators-may-come-from)
- [Mongoid query builder NoSQL injection via string criteria](https://junglewise.ai/threats/cve-2026-93759-mongoid-does-not-neutralize-a-string-typed-query-criterion)
- [Mongoid unsafe reflection in document persistence layer](https://junglewise.ai/threats/cve-2026-93765-mongoid-contains-an-unsafe-reflection-weakness-in-the-document)