# CVE-2026-92757: MongoDB Entity Framework Core Provider field encryption bypass via database name misconfiguration

Source: https://junglewise.ai/threats/cve-2026-92757-mongodb-entity-framework-core-provider-field-encryption-bypass  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-17. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-92757 · Severity: medium · CVSS 5.5 · Published 2026-09-17

MongoDB Entity Framework Core Provider is a library that allows .NET applications to interact with MongoDB databases. When developers configure the library with a database name in the connection string (a documented and supported approach), the field-level encryption feature silently fails to activate, causing all supposedly encrypted sensitive data to be stored in plaintext in the database. This exposes customer data, payment card information, and other confidential records to database administrators, backup systems, and potential attackers.

Technologies: [MongoDB Entity Framework Core Provider](https://junglewise.ai/threats/technologies/entity-framework-core-provider). Vendors: [MongoDB](https://junglewise.ai/threats/vendors/mongodb).

## Quick answers

**Is CVE-2026-92757 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-92757 being exploited in the wild.

**How severe is CVE-2026-92757?** Medium severity, with a CVSS score of 5.5, published 17 September 2026.

**Which products and versions are affected?** MongoDB Entity Framework Core Provider before 8.4.4, 9.x before 9.1.4, 10.x before 10.0.4.

**Is there a fix for CVE-2026-92757?** A patch was published on 2026-09-17: Fixes available in versions 8.4.4, 9.1.4, and 10.0.4 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-92757 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-92757?** Check whether you run MongoDB Entity Framework Core Provider 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.

## Technical details

The vulnerability is a configuration validation failure in the connection string handling code. When a database name is provided in the MongoDB connection string URI, the GetOrCreateMongoClient method resolves the database name from the URI into an internal _databaseName variable, but passes the unmodified options object (with DatabaseName field still null) to the CreateSettings method. CreateSettings then constructs encryption field map keys as "null.collectionName" instead of "appdb.collectionName", causing the encryption schema to be applied to non-existent namespaces. Consequently, when actual CRUD operations target the real namespace (e.g., "appdb.People"), the encryption map fails to match and all declared-encrypted fields are silently stored and retrieved as plaintext. No error or warning is surfaced to the application. The root cause is the missing validation in MongoOptionsExtension.Validate and the disconnection between the resolved _databaseName and the CreateSettings invocation. Fix is available in versions 10.0.4, 9.1.4, and 8.4.4.

## Affected products

- MongoDB Entity Framework Core Provider before 8.4.4, 9.x before 9.1.4, 10.x before 10.0.4

## Timeline

- 2026-09-17: disclosed
- 2026-09-17: patched: Fixes available in versions 8.4.4, 9.1.4, and 10.0.4

## References

- [https://jira.mongodb.org/browse/EF-389](https://jira.mongodb.org/browse/EF-389)

## Related threats

- [MongoDB Entity Framework Core provider expression injection in bulk update](https://junglewise.ai/threats/cve-2026-120567-the-mongodb-entity-framework-core-provider-does-not-neutralize)
- [MongoDB Entity Framework Core credential exposure in logging](https://junglewise.ai/threats/cve-2026-92758-mongodb-entity-framework-core-credential-exposure-in-logging)
- [MongoDB Entity Framework Core Provider encryption settings bypass](https://junglewise.ai/threats/cve-2026-92756-mongodb-entity-framework-core-provider-encryption-settings-bypass)