CVE-2026-81528 — NoSQL injection via array replacement bypassing update shape validation in driver write path

Description (CNA)

A MongoDB C# driver document-replacement code path omits the element-name/shape validation that the equivalent write paths apply, so a value supplied as a replacement is forwarded to the server without neutralization of query-language special elements. An application that passes untrusted, loosely-typed input as a replacement value therefore allows that input to be interpreted by the database as update logic rather than as data, executing under the application's own database credentials. Applications using strongly-typed document mappings are not affected.

Affected (CNA)

Vendor / product	Versions
MongoDB / C# Driver	affected 2.9.0 before 3.11.1

CWE

CWE-943

References

https://jira.mongodb.org/browse/CSHARP-6158
https://www.nuget.org/packages/MongoDB.Driver/3.11.1

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.