{"id":"CVE-2026-81529","title":"Improper neutralization of delimiters in connection-URL construction allows connection-option injection in the MongoDB C# Driver","summary":"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 buil…","severity":"high","cvss":7.1,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N","cwe":["CWE-88"],"vendor":"mongodb","product":"c#_driver","affected":["c#_driver >= 2.10.0, < 3.11.1"],"patched":["c#_driver 3.11.1"],"published":"2026-08-27","updated":"2026-09-29","sourceUpdated":"2026-09-29T19:16:22.150","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-81529","references":[{"url":"https://jira.mongodb.org/browse/CSHARP-6171","label":"cna@mongodb.com"},{"url":"https://www.nuget.org/packages/MongoDB.Driver/3.11.1","label":"cna@mongodb.com"}],"tags":["nvd"],"epss":0.00278,"epssPercentile":0.1823,"ingestedAt":"2026-09-29T19:44:04.118Z","slug":"CVE-2026-81529","body":"## Overview\n\nImproper 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.\n\n## Affected\n\n- `c#_driver >= 2.10.0, < 3.11.1`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `c#_driver 3.11.1`","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":39.1,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}