CVE-2026-18690: Improper Authorization in MongoDB Server Allows Unauthorized Actions on System Collections

Severity: high (CVSS 8.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-11 · updated 2026-10-23
Weakness: CWE-863

Description

An issue in MongoDB Server could allow an authenticated user with a limited database-scoped role to perform an action against protected system collections that their assigned privileges should not permit. This could result in critical system collections being dropped and recreated without proper authorization.

Affected products

MongoDB: from 7.0.0 before 7.0.40; from 8.0.0 before 8.0.29; from 8.2.0 through 8.2.12; from 8.3.0 before 8.3.8; 9.0.0-alpha0, 9.0.0-alpha1, 9.1.0-alpha0 — fixed in 7.0.40, 8.0.29, 8.3.8

How to fix

Upgrade to a fixed version: MongoDB 7.0.40, 8.0.29, 8.3.8. Check the vendor advisory for mitigations.

References

https://jira.mongodb.org/browse/SERVER-130481

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