# CVE-2026-104004: MongoDB Server denial of service in collection validation

Source: https://junglewise.ai/threats/cve-2026-104004-mongodb-server-s-collection-validation-feature-may-not-properly  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-13. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-104004 · Severity: medium · CVSS 6.5 · Published 2026-10-13

MongoDB Server, a widely-used NoSQL database, has a flaw in its collection validation feature that can crash the database process when certain malformed validation rules are used. An authenticated database user with write permissions can trigger a server crash by inserting a document that matches a specifically-crafted validator expression, causing an outage until the server is manually restarted.

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

## Quick answers

**Is CVE-2026-104004 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-104004 being exploited in the wild.

**How severe is CVE-2026-104004?** Medium severity, with a CVSS score of 6.5, published 13 October 2026.

**Which products and versions are affected?** MongoDB Server before 8.0.34, 8.3.13, 9.0.4, and 9.1.0-rc1024.

**Is there a fix for CVE-2026-104004?** Yes: fixed in 8.0.34, 8.3.13, 9.0.4, 9.1.0-rc1024. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-104004 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-104004?** 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 8.0.34, 8.3.13, 9.0.4, 9.1.0-rc1024

## Technical details

The collection validation feature in MongoDB Server improperly processes certain expressions stored in validators, leading to a denial of service. An authenticated attacker with write access can insert a document that triggers the vulnerable code path in the validation layer, causing the server process to terminate. A fix is available in MongoDB Server 8.0.34, 8.3.13, 9.0.4, and 9.1.0-rc1024 or later.

## Affected products

- MongoDB Server before 8.0.34, 8.3.13, 9.0.4, and 9.1.0-rc1024

## Timeline

- 2026-10-13: disclosed
- 2026-10-12: patched

## References

- [https://jira.mongodb.org/browse/SERVER-131412](https://jira.mongodb.org/browse/SERVER-131412)

## 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)