CVE-2026-81527

A NoSQL/expression injection weakness exists in the LINQ-to-aggregation query translation layer of the MongoDB C# Driver, in both aggregation expression and query filter translation. When application-supplied values are embedded in certain query constructs, special elements contained within those values are not properly escaped before the resulting query is transmitted to the database, so portions of the value may be interpreted by the database as query logic rather than as data. A user able to supply values that an application incorporates into an affected query may thereby cause unintended data to be returned or query results to be altered.

Scoring

Severity
MEDIUM
CVSS base score
6.9
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
EPSS probability
0.18%
CWE
CWE-943
Published
2026-08-27
Last modified
2026-08-28

Affected products

Weakness type

Markdown version · Browse all CVEs