Description

An issue in MongoDB Server's Queryable Encryption maintenance operations could allow an authenticated user with privileges on one encrypted collection to cause unauthorized modification or destruction of data belonging to a different collection. This is due to insufficient validation of certain internal metadata references before they are used to perform operations on other namespaces.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.1",
  "pubDate": "2026-08-11T19:17:29.360Z",
  "pubdate": "2026-08-11T19:17:29.360Z",
  "executiveSummary": "An improper validation vulnerability exists in MongoDB Server within the Queryable Encryption maintenance operations. This security flaw permits an authenticated user who possesses specific privileges on a single encrypted collection to execute unauthorized data modification or total data destruction against distinct, unrelated encrypted collections. The root of the issue lies in the handling of internal metadata references, which fail to undergo rigorous validation before being leveraged to execute namespace-level operations. The impact of successful exploitation includes integrity compromise and data loss across tenant boundaries or restricted database namespaces. The threat actor profile requires authenticated access to the database system along with preliminary privileges on at least one legitimately assigned encrypted collection. Exploitation requirements necessitate the manipulation or targeting of internal metadata structures to redirect maintenance operations toward arbitrary namespaces. Risk implications are severe for multi-tenant or highly segregated environments utilizing Queryable Encryption, as access controls designed to isolate encrypted collections can be bypassed through this metadata reference flaw. Affected systems are limited to instances of MongoDB Server supporting Queryable Encryption maintenance features.",
  "technicalDetails": "The vulnerability resides within the internal components of MongoDB Server responsible for executing Queryable Encryption maintenance operations. The vulnerable component fails to adequately validate internal metadata references prior to initiating operations against specified target namespaces. During standard maintenance routines, the system processes metadata to locate and manage state information for encrypted collections. Due to insufficient input sanitization and namespace verification checks, an authenticated adversary with valid privileges on a controlled, legitimate encrypted collection can supply maliciously crafted or manipulated internal metadata references. The attack flow commences when the attacker initiates a maintenance operation with these altered metadata references. Because the underlying logic trusts the supplied reference without properly verifying ownership or namespace boundaries, the server's processing engine interprets the reference as pointing to a different, victim-controlled or protected collection namespace. Consequently, subsequent maintenance commands execute against the unintended namespace. The post-exploitation impact allows the malicious actor to perform unauthorized data modifications, structural corruption, or complete data destruction on collections where they possess no direct privileges or access rights. The vector requires prior authentication to the database server and existing privileges scoped to an encrypted collection, eliminating unauthenticated external network exposure vectors while creating a significant escalation of privilege and lateral data destruction path within the database environment."
}