CVE-2026-82069 in Server
Summary
by MITRE • 09/08/2026
A security issue in MongoDB Server's query statistics serialization on the router allows users with monitoring privileges to access unredacted search query text from other users' operations. An improper conditional check in the serialization logic causes the data redaction mechanism to be bypassed when processing search queries through the sharded cluster router. This results in sensitive query literals being stored and made accessible through the query statistics interface.
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Analysis
by VulDB Data Team • 09/08/2026
The vulnerability described involves a critical flaw within MongoDB Server's handling of query statistics serialization, specifically affecting operations processed through the sharded cluster router. In distributed database environments like MongoDB sharded clusters, client requests are routed to specific shards based on shard key values. The router acts as an intermediary that aggregates and manages these queries across multiple nodes. During this process, MongoDB employs a data redaction mechanism designed to sanitize sensitive information from query logs and statistics interfaces. This mechanism is intended to prevent the exposure of personally identifiable information or other confidential literals contained within user queries when those results are viewed by users with monitoring privileges. However, due to an improper conditional check in the serialization logic, this security control fails under specific conditions related to search query processing.
The technical root cause lies in a logical error where the redaction routine is bypassed rather than executed correctly for certain types of incoming queries. When a user submits a search query that triggers the affected code path within the router's statistics collection module, the system incorrectly determines that no sensitive data requires masking. Consequently, the raw, unredacted text of the query literal is persisted in the internal structures used to track query performance and history. This means that instead of seeing sanitized placeholders or masked values, any user with access to the monitoring tools can view the exact string content submitted by other users during their search operations.
The operational impact of this vulnerability is significant for organizations relying on MongoDB for sensitive data processing. Users who possess monitoring privileges, such as database administrators or DevOps engineers tasked with performance tuning and troubleshooting, gain unauthorized visibility into the actual query payloads executed by application servers or end-users. This constitutes a violation of confidentiality principles, potentially exposing trade secrets, customer personal information, or internal business logic embedded within search parameters. In regulated industries where data privacy is mandated by standards such as GDPR or HIPAA, this exposure could lead to compliance failures and legal repercussions. Furthermore, attackers who have compromised an account with monitoring rights can leverage this flaw for reconnaissance purposes, gathering intelligence on how other applications interact with the database schema and identifying potential targets for further exploitation based on observed query patterns.
From a classification perspective, this issue aligns with CWE-209: Generation of Error Message Containing Sensitive Information, as it involves the leakage of sensitive data through system outputs intended for administrative monitoring. It also relates to CWE-778: Insufficient Logging or Monitoring if considered in terms of audit trail integrity, though the primary flaw is more accurately categorized under CWE-200: Exposure of Sensitive Information to an Unauthorized Actor due to improper access control logic within a specific feature set. In the context of the MITRE ATT&CK framework for enterprise security, this vulnerability facilitates information discovery techniques where adversaries gather data about database structures and application behavior through legitimate administrative interfaces that have been compromised or misconfigured.
Mitigation strategies must address both immediate remediation and long-term architectural improvements. The primary solution is to apply the vendor-provided patch or upgrade to a version of MongoDB Server where the conditional check in the serialization logic has been corrected to ensure redaction occurs consistently for all query types, including those processed via sharded routers. Organizations should verify their current server versions against known vulnerable releases and prioritize updates during maintenance windows. Additionally, access control policies should be reviewed to ensure that monitoring privileges are granted only to personnel who strictly require them, adhering to the principle of least privilege. Implementing strict role-based access controls can limit the blast radius if such a vulnerability is exploited in the future.
Beyond patching, defensive measures include enhancing audit logging capabilities to detect unusual patterns of query statistic retrieval or redaction failures. Security teams should monitor for anomalies in administrative account activity that might indicate exploitation attempts. Regular security assessments and penetration testing focused on data leakage vectors within database administration interfaces are recommended to identify similar logical flaws before they can be exploited by malicious actors. Ensuring that all components involved in the request lifecycle, including routers, shards, and monitoring tools, are consistently updated is essential for maintaining a robust defense-in-depth posture against information disclosure vulnerabilities.