# CVE-2026-82076: MongoDB Server integer overflow in query planner

Source: https://junglewise.ai/threats/cve-2026-82076-mongodb-server-integer-overflow-in-query-planner  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-08. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-82076 · Severity: medium · CVSS 6.5 · Published 2026-09-08

MongoDB Server is a widely-used document database engine. An authenticated attacker can submit a specially crafted query that causes the query planning component to crash, resulting in denial of service and making the database temporarily unavailable. The attack requires only standard read/write database privileges and no special configuration.

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

## Quick answers

**Is CVE-2026-82076 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-82076 being exploited in the wild.

**How severe is CVE-2026-82076?** Medium severity, with a CVSS score of 6.5, published 8 September 2026.

**Which products and versions are affected?** MongoDB Server 7.0.0 through 7.0.40, 8.0.0 through 8.0.29, 8.2.0 through 8.2.6, 8.3.0 through 8.3.8, 9.0.0-rc0 and rc1.

**Is there a fix for CVE-2026-82076?** A patch was published on 2026-09-08: Patched in versions 7.0.41, 8.0.30, 8.2.13, 8.3.9, 9.0.0-rc2 and later Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-82076 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-82076?** 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.

## Technical details

An integer overflow vulnerability exists in MongoDB's QueryPlannerAnalysis::explodeForSort() function in src/mongo/db/query/planner_analysis.cpp. When processing a find().sort() query with multiple $in predicates containing large numbers of values, the planner multiplies the point-interval counts without overflow checking. With eight $in predicates of 256 values each, the calculation 256^8 wraps to 0 on 64-bit systems, bypassing the maxScansToExplode safety guard. The planner then proceeds into Cartesian product materialization, causing unbounded memory consumption and process termination. Attack requires authenticated database access and a collection with a suitable compound index; the fix is available in MongoDB 7.0.41, 8.0.30, 8.2.13, 8.3.9, and 9.0.0-rc2 or later.

## Affected products

- MongoDB MongoDB Server 7.0.0 through 7.0.40, 8.0.0 through 8.0.29, 8.2.0 through 8.2.6, 8.3.0 through 8.3.8, 9.0.0-rc0 and rc1

## Timeline

- 2026-09-08: disclosed: Public disclosure via NVD
- 2026-09-08: patched: Patched in versions 7.0.41, 8.0.30, 8.2.13, 8.3.9, 9.0.0-rc2 and later

## References

- [https://jira.mongodb.org/browse/SERVER-128253](https://jira.mongodb.org/browse/SERVER-128253)

## 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)