CVE-2026-93761: MongoDB Mongoid

High severity, CVSS 7.5. EPSS: 0.5% chance of exploitation in the next 30 days.

An inefficient regular expression complexity issue in the in-memory query evaluation component of the Mongoid library may allow an unauthenticated party to cause excessive processing within an embedding application process. Applications that place user-supplied text into a pattern-matching query condition on an embedded association may become unresponsive.

Affected products

• MongoDB Mongoid: from 8.0.0, before 8.0.13 (fixed in 8.0.13); from 8.1.0, before 8.1.13 (fixed in 8.1.13); from 9.0.0, before 9.0.12 (fixed in 9.0.12); version 9.1.0 only

Published 2026-09-18. Last modified 2026-09-24.