Vulnerability · Published Jun 9, 2026 · Assigned by mongodb

CVE-2026-9743Aggregation sub-pipeline null dereference may allow DoS via crafted getMore

Medium 6.5

In plain English

A medium-severity null pointer dereference in MongoDB server from MongoDB. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 24% of all known vulnerabilities).

Severity (CVSS 3.1)6.5Medium

Exploit odds (30 days)0.3%top 76.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

In MongoDB Server 8.0, an aggregation stage can leave its _subPipeline field null during processing of certain pipelines. If a getMore is subsequently issued on the same cursor, the server may dereference this null sub-pipeline when reattaching to the operation context, accessing an invalid address and crashing the process. This issue allows an authenticated user who can run aggregation pipelines to cause a denial of service by issuing a specially crafted aggregation followed by getMore on affected versions.

Affected products (as reported)

Vendor	Product	Versions
MongoDB	MongoDB server	8.0.0 – before 8.0.24

Weakness: CWE-476 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References

https://jira.mongodb.org/browse/SERVER-123688