CVE-2026-81529

Connection-option injection via unescaped settings in the canonical MongoDB URL builder

Published Aug 27, 2026 CVSS 4.0 · 7.1 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Mongodb c\# Driver
CPEs cpe:2.3:a:mongodb:c\#_driver:*:*:*:*:*:mongodb:*:*
Vendors & Products Mongodb c\# Driver
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Mongodb
Mongodb c# Driver
Vendors & Products Mongodb
Mongodb c# Driver
Type Values Removed Values Added
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.
Title Connection-option injection via unescaped settings in the canonical MongoDB URL builder
Weaknesses CWE-88
References
Metrics cvssV3_1

{'score': 7.1, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N'}

cvssV4_0

{'score': 7.1, 'vector': '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
mongodb
Published
Updated
Aug 28, 2026, 4:37 PM
Reserved
Aug 26, 2026, 10:14 PM
Status
Analyzed
Published
Aug 27, 2026, 8:18 PM
Modified
Sep 29, 2026, 7:16 PM