# CVE-2026-81529

## Summary

- **CVE ID:** CVE-2026-81529
- **Severity:** HIGH
- **CVSS Score:** 7.1 (CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:H/SI:L/SA:N)
- **CWE:** CWE-88
- **Published:** Aug 27, 2026
- **Last Modified:** Aug 28, 2026

## Description

Improper neutralization of delimiters in connection-URL construction allows connection-option injection in the MongoDB C# Driver. When an application passes untrusted text into the driver's connection-URL builder and round-trips the builder back into a client configuration, the untrusted text is serialized without neutralizing the URL/option delimiters and is then re-parsed as authoritative connection options. A low-privileged user of such an application can thereby introduce or suppress security-relevant connection settings.

## Affected Products

- MongoDB — C# Driver (3.5.0)
- MongoDB — C# Driver (2.0.0)

## References

- [CNA](https://www.nuget.org/packages/MongoDB.Driver/3.11.1)
- [CNA](https://jira.mongodb.org/browse/CSHARP-6171)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.17%
- **EPSS Percentile:** 7.0

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._