# CVE-2026-120819: MongoDB Server memory disclosure in JavaScript execution

Source: https://junglewise.ai/threats/cve-2026-120819-a-memory-management-flaw-in-the-server-side-javascript-execution  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-10. Updated: 2026-11-10  
License: CC BY 4.0 with a link back

CVE-2026-120819 · Severity: medium · CVSS 4.3 · Published 2026-11-10

MongoDB Server, a popular database platform, contains a memory-safety flaw in its server-side JavaScript execution engine. An authenticated user with only read permissions can exploit this by submitting a specially crafted database command to read sensitive data from the server's memory that they are not authorized to access, potentially exposing secrets or other confidential information.

Technologies: [MongoDB Server](https://junglewise.ai/threats/technologies/mongodb-server). Vendors: [MongoDB](https://junglewise.ai/threats/vendors/mongodb).

## Quick answers

**Is CVE-2026-120819 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-120819 being exploited in the wild.

**How severe is CVE-2026-120819?** Medium severity, with a CVSS score of 4.3, published 10 November 2026.

**Which products and versions are affected?** MongoDB Server prior to 9.0.7.

**Is there a fix for CVE-2026-120819?** Yes: fixed in 9.0.7. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-120819 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-120819?** Check whether you run MongoDB Server 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.

## How to fix

- Fixed in 9.0.7

## Technical details

A memory-management flaw in MongoDB Server's server-side JavaScript execution component allows an authenticated read-only user to access freed memory via a specially crafted database command. The vulnerability returns a bounded amount of adjacent process memory in the command result, enabling information disclosure. The flaw affects the BSON generation in the WASM bridge component.

## Affected products

- MongoDB Server prior to 9.0.7

## Timeline

- 2026-11-10: disclosed
- 2026-09-30: patched

## References

- [https://jira.mongodb.org/browse/SERVER-134893](https://jira.mongodb.org/browse/SERVER-134893)

## Related threats

- [MongoDB Server authorization bypass in aggregation pipeline](https://junglewise.ai/threats/cve-2026-120825-an-authorization-weakness-in-the-aggregation-framework-of)
- [MongoDB Server use-after-free in time-series bucket validation](https://junglewise.ai/threats/cve-2026-120824-a-use-after-free-in-the-time-series-collection-component-of)
- [MongoDB Server missing authorization check in aggregation framework](https://junglewise.ai/threats/cve-2026-120823-a-missing-authorization-check-in-the-aggregation-framework-of)
- [MongoDB Server authorization bypass in applyOps](https://junglewise.ai/threats/cve-2026-120822-mongodb-server-may-omit-an-authorization-check-on-the-resource)
- [MongoDB Server use-after-free in aggregation framework](https://junglewise.ai/threats/cve-2026-120821-a-use-after-free-in-the-aggregation-framework-of-mongodb-server)