Description

An issue in MongoDB Server could allow an authenticated user, including one with no assigned privileges, to cause the server process to terminate unexpectedly by submitting a specially formed aggregation command. This could result in a denial of service.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "4.3",
  "pubDate": "2026-08-11T19:17:25.517Z",
  "pubdate": "2026-08-11T19:17:25.517Z",
  "executiveSummary": "An unprivileged denial of service vulnerability exists within the MongoDB Server aggregation pipeline processing engine. The flaw allows an authenticated user, regardless of assigned privileges or authorization levels, to trigger an abnormal server process termination.\nBy submitting a maliciously crafted aggregation command to the database, an adversary can exhaust server resources or trigger unhandled execution exceptions, directly impacting database availability.\nThe affected system is the MongoDB Server process. Because exploitation requires only basic authentication without specific role-based privileges, the risk profile is elevated for environments that allow untrusted or broad user access.\nThe primary operational impact is a complete loss of service availability due to unexpected process termination, which may disrupt dependent applications and services connecting to the database instance.",
  "technicalDetails": "The vulnerability resides within the aggregation command parsing and execution component of MongoDB Server. The root cause stems from improper input validation and exception handling when processing specially formed aggregation commands.\nExploitation requires the attacker to possess valid credentials to authenticate against the MongoDB database instance. However, no specialized administrative roles or privileges are required; users with zero assigned privileges can successfully execute the attack vector.\nThe attack flow begins when an authenticated client establishes a session with the MongoDB Server and issues a crafted aggregation command containing malicious structure or parameters. Upon receiving the payload, the vulnerable aggregation engine parses the command and enters an execution path that triggers an unhandled segmentation fault, assertion failure, or critical exception.\nBecause the runtime environment fails to gracefully catch or manage the resulting error condition, the MongoDB Server process terminates abruptly. This causes an immediate denial of service for all concurrent database operations and active client connections.\nNetwork exposure depends on the database deployment configuration, but typically involves TCP/IP network access to the MongoDB port. Post-exploitation impact is limited to availability disruption, as remote code execution or unauthorized data access is not described by the vulnerability mechanism."
}