Answer in brief
CVE-2026-81528 records a Medium severity (CVSS 5.4) vulnerability in NoSQL injection via array replacement bypassing update shape validation in driver write path. The current sources do not mark it as known exploited. The current feed maps MongoDB/C# Driver (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.4. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps MongoDB/C# Driver (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:a:mongodb:c\#_driver:*:*:*:*:*:mongodb:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| MongoDB/C# Drivergeneric | >=2.9.0 <3.11.1 | 3.11.1 |
Published upstream
Aug 27, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 29, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 27, 2026
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.
Quoted source text, attributed separately from HOL analysis.