CVE-2026-18697 PUBLISHED

Improper Input Validation in MongoDB Aggregation Framework Allows Unauthenticated Denial of Service on mongos

Assigner: mongodb
Reserved: 03.08.2026 Published: 11.08.2026 Updated: 11.08.2026

An issue in MongoDB Server's aggregation framework could allow an unauthenticated party to cause a mongos (router) process to terminate unexpectedly by submitting a specially formed aggregation command. This could result in a denial of service, disrupting client connections routed through the affected mongos instance.

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CVSS Score: 8.7

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	None	Integrity	None
Attack Requirements	None	Availability	High	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS Score: 7.5

Attack Vector	Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	None
Privileges Required	None	Integrity Impact	None
User Interaction	None	Availability Impact	High

CVSS 3.1

Product Status

Vendor	MongoDB
Product	MongoDB Server
Versions	Default: unaffected affected from 8.3.0 to 8.3.8 (excl.) affected from 8.0 to 8.0.29 (excl.) affected from 7.0 to 7.0.40 (excl.)

References

https://jira.mongodb.org/browse/SERVER-130110

Problem Types

CWE-617: Reachable Assertion CWE