CVE-2026-82069: MongoDB Server Information Disclosure Flaw

CVE-2026-82069 Overview

CVE-2026-82069 is an information disclosure vulnerability in MongoDB Server's query statistics serialization on the sharded cluster router. An improper conditional check in the serialization logic bypasses the data redaction mechanism when processing search queries. Users with monitoring privileges can read unredacted search query text belonging to other users' operations. The exposed data includes sensitive query literals stored in the query statistics interface. The issue is tracked in MongoDB Jira as SERVER-132835 and is classified under [CWE-212: Improper Removal of Sensitive Information Before Storage or Transfer].

Critical Impact
Authenticated users with monitoring privileges can obtain unredacted query literals from other users' search operations processed through the sharded cluster router, exposing potentially sensitive data.

Affected Products

MongoDB Server (sharded cluster router / mongos component)
Query statistics serialization subsystem
Deployments exposing $queryStats to monitoring roles

Discovery Timeline

2026-09-08 - CVE-2026-82069 published to NVD
2026-09-08 - Last updated in NVD database

Technical Details for CVE-2026-82069

Vulnerability Analysis

MongoDB Server collects query statistics through the $queryStats aggregation stage. The system redacts literal values from queries before persisting them so that shape-based analysis does not leak user data. On the mongos router, the serialization path handling search queries contains an improper conditional check. When the check evaluates incorrectly, the redaction step is skipped and raw query literals are written into the statistics store. Any principal holding a role with monitoring privileges can then read the unredacted content through the query statistics interface.

The exposure affects search queries routed through sharded clusters. Because query statistics are aggregated across users, a single monitoring-privileged account can view literals originating from other operators and applications. This crosses a tenant boundary that MongoDB's redaction feature is designed to enforce.

Root Cause

The root cause is an improper conditional check in the serialization logic on the sharded cluster router. The condition intended to trigger literal redaction for search queries evaluates incorrectly and the code path bypasses the redaction routine. Sensitive query text is then serialized and stored verbatim. Additional technical detail is available in the MongoDB Jira Issue SERVER-132835.

Attack Vector

Exploitation requires network access to mongos and authenticated credentials with monitoring privileges, such as roles granting the $queryStats action. No user interaction is required. The attacker issues a standard aggregation against the query statistics collection and reads the returned documents. Impact is limited to confidentiality of query literals; integrity and availability are not affected.

No public proof-of-concept exploit code is available for this issue.

Detection Methods for CVE-2026-82069

Indicators of Compromise

Aggregation commands invoking the $queryStats stage from accounts that do not normally perform performance analysis.
Unusual volumes of read operations against query statistics data by monitoring or diagnostic service accounts.
Query statistics documents on mongos containing literal values rather than redacted placeholders for search query fields.

Detection Strategies

Audit MongoDB mongos logs for $queryStats invocations and correlate the calling principal with expected monitoring workflows.
Sample stored query statistics on the router and verify that search query literals appear in redacted form.
Review role definitions granting the $queryStats privilege and flag accounts holding this privilege that are not part of the observability tier.

Monitoring Recommendations

Enable MongoDB auditing for administrative and diagnostic commands, then forward audit records to a central log platform for retention and analysis.
Alert on privilege grants that add the $queryStats action to non-administrator roles.
Track baseline access patterns to query statistics and alert on deviation, particularly from application service accounts.

How to Mitigate CVE-2026-82069

Immediate Actions Required

Inventory all roles that grant access to $queryStats on sharded clusters and remove the privilege from accounts that do not require it.
Restrict monitoring role assignment to trusted operators and enforce multi-factor authentication for those principals.
Rotate any credentials or secrets that may have appeared as literals inside recent search queries executed against sharded clusters.

Patch Information

Refer to the MongoDB Jira Issue SERVER-132835 for fixed version details and upgrade guidance. Apply the vendor-supplied patch to mongos binaries across all shards and routers, then validate that new search queries recorded in query statistics show redacted literals.

Workarounds

Disable or scope down $queryStats collection on mongos where operationally feasible until patched binaries are deployed.
Restrict access to the query statistics interface using MongoDB role-based access control so that only a small set of administrative principals can invoke it.
Segment monitoring accounts from application accounts to prevent cross-tenant exposure of query literals.

bash

# Configuration example: revoke $queryStats from a monitoring role
use admin
db.revokePrivilegesFromRole(
  "customMonitorRole",
  [ { resource: { cluster: true }, actions: [ "queryStatsRead" ] } ]
)