Vulnerability · Published Sep 8, 2026 · Assigned by mongodb
CVE-2026-82060Insufficient Validation of Shard Key Values in MongoDB Server Leads to Query Operator Injection in Change Stream Post-Image Lookups
Medium 5.4
In plain English
A medium-severity security flaw 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 28% of all known vulnerabilities).
Official description
In MongoDB, insufficient validation of shard key values during document insertion allowed authenticated users to store documents with specially crafted, operator-shaped objects as shard key values in sharded collections. When change stream events for such documents were processed with the updateLookup full document mode, the crafted values were embedded into internal post-image lookup queries without proper sanitization, causing them to be interpreted as query operators rather than literal equality values. This could result in change stream consumers receiving incorrect post-image documents or encountering non-resumable fatal errors.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| MongoDB | MongoDB Server | 8.3.0 – before 8.3.98.0.0 – before 8.0.307.0.0 – before 7.0.41 |
Weakness: CWE-943 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L