CVE-2026-81529: Connection-option injection via unescaped settings in the canonical MongoDB URL builder
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.
Vector CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N · CWE-88
Tracked companies
Mapped from the CVE’s affected-product data, NVD CPE matches, vendor advisories or package feeds. A mapping means the vendor’s software is named, not that its hosted service was exposed.
Status incidents that name it
No tracked status incident names this CVE.
Affected vendors and products
MongoDB: C# Driver
References
- CVE record on cve.org (opens in new tab)
- NVD entry (opens in new tab)
- jira.mongodb.org/browse/CSHARP-6171 (opens in new tab)
- www.nuget.org/packages/MongoDB.Driver/3.11.1 (opens in new tab)
- CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (opens in new tab)
- This product uses data from the NVD API but is not endorsed or certified by the NVD. (opens in new tab)
- Known Exploited Vulnerabilities catalog from CISA. (opens in new tab)
- EPSS scores from FIRST (Exploit Prediction Scoring System). (opens in new tab)