# CVE-2026-93765: Mongoid unsafe reflection in document persistence layer

Source: https://junglewise.ai/threats/cve-2026-93765-mongoid-contains-an-unsafe-reflection-weakness-in-the-document  
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-2026-93765 · Severity: critical · CVSS 9.1 · Published 2026-09-18

Mongoid, a Ruby library for interacting with MongoDB databases, contains a weakness that allows unauthenticated attackers to invoke unintended internal methods through specially crafted input keys. An attacker can exploit this to delete database records and cause the application using Mongoid to stop responding, impacting both data integrity and application availability.

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

## Quick answers

**Is CVE-2026-93765 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-93765 being exploited in the wild.

**How severe is CVE-2026-93765?** Critical severity, with a CVSS score of 9.1, published 18 September 2026.

**Which products and versions are affected?** MongoDB Mongoid <UNKNOWN>.

**Is there a fix for CVE-2026-93765?** 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-2026-93765 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-93765?** Check whether you run MongoDB Mongoid 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 an unsafe reflection weakness in the document persistence layer's object-document mapping code. Unauthenticated input with malicious keys can bypass intended array field update logic and trigger internal method invocation, leading to unintended record removal and denial of service. The flaw affects how Mongoid processes embedded document updates when keys are passed through from an untrusted source.

## Affected products

- MongoDB Mongoid <UNKNOWN>

## Timeline

- 2026-09-18: disclosed

## References

- [https://jira.mongodb.org/browse/MONGOID-5973](https://jira.mongodb.org/browse/MONGOID-5973)

## Related threats

- [Mongoid client-side encryption omission in embedded models](https://junglewise.ai/threats/cve-2026-93764-mongoid-may-omit-encryption-rules-for-fields-declared-on-embedded)
- [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)