This vulnerability (CVE-2026-13062) involves an authenticated user with write privileges on a Queryable Encryption-enabled collection in MongoDB Server. By sending specially crafted write commands through the mongos router in a sharded cluster environment, the user may modify internal encryption metadata fields that are intended to be controlled solely by the server. This can lead to corruption of encrypted query correctness, potentially impacting data integrity or query results. The issue affects specific versions of MongoDB Server (7.0, 8.0, 8.2.0, and 8.3.0). No vendor advisory or patch information is currently available.

An attacker with authenticated write access can manipulate internal encryption metadata fields, which are supposed to be server-controlled, causing corruption in encrypted query correctness. This may affect the reliability and integrity of encrypted queries on Queryable Encryption-enabled collections in sharded MongoDB clusters. There is no indication of privilege escalation or data disclosure beyond this impact.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, restrict write privileges on Queryable Encryption-enabled collections to trusted users only and monitor for unusual write commands through the mongos router. Avoid deploying affected versions in sensitive environments if possible.