CVE-2026-81529: mongodb c_driver Argument Injection

Vulnerability summary

CVE-2026-81529 is a high (CVSS 7.1) Argument Injection vulnerability in mongodb c_driver. EPSS estimates a 0.29% chance of exploitation in the next 30 days, higher than 19.7% of scored vulnerabilities.

Timeline

1. 27-08-2026
   PublishedVulnerability first disclosed.
2. 28-08-2026
   Last modifiedVulnerability information updated.

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.

• CWE-88Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')The product constructs a string for a command to be executed by a separate component in another control sphere, but it does not properly delimit the intended arguments, options, or switches within that command string.