# CVE-2026-120812: MongoDB Server denial of service in query processing

Source: https://junglewise.ai/threats/cve-2026-120812-an-issue-in-mongodb-server-s-query-processing-component-allows  
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-2026-120812 · Severity: medium · CVSS 6.5 · Published 2026-11-10

MongoDB Server contains a flaw in its query processing component that allows authenticated users with read access to crash the database server by submitting specially crafted queries against time-series collections. The vulnerability exploits uncontrolled recursion in the internal query compilation logic, leading to stack exhaustion and server termination. An attacker with legitimate database credentials and read permissions could trigger this denial of service.

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

## Quick answers

**Is CVE-2026-120812 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-120812 being exploited in the wild.

**How severe is CVE-2026-120812?** Medium severity, with a CVSS score of 6.5, published 10 November 2026.

**Which products and versions are affected?** MongoDB Server before 8.3.16 and 9.0.x before 9.0.7.

**Is there a fix for CVE-2026-120812?** Yes: fixed in 8.3.16, 9.0.7. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-120812 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-120812?** 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 8.3.16, 9.0.7

## Technical details

Uncontrolled recursion in the query compilation component (ABT tree generation and manipulation) can exhaust stack space when processing certain queries against time-series collections, causing server process termination. The vulnerability requires authentication and read-level database privileges. An attacker gains a denial of service condition affecting database availability.

## Affected products

- MongoDB Server before 8.3.16 and 9.0.x before 9.0.7

## Timeline

- 2026-11-10: disclosed
- 2026-11-10: patched

## References

- [https://jira.mongodb.org/browse/SERVER-131961](https://jira.mongodb.org/browse/SERVER-131961)

## 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)