Vulnerability · Published Aug 11, 2026 · Assigned by mongodb

CVE-2026-18687Improper Validation in MongoDB Queryable Encryption Maintenance Operation Leads to Denial of Service and Index Corruption

High 7.1

In plain English

A high-severity security flaw in MongoDB Server from MongoDB. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 14% of all known vulnerabilities).

Severity (CVSS 3.1)7.1High

Exploit odds (30 days)0.2%top 85.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

MongoDB Server's handling of a Queryable Encryption maintenance operation did not properly validate certain request parameters against the collection's encrypted field configuration before use. An authenticated user with readWrite privileges could submit a specially formed request that leads to a server crash or excessive internal writes, resulting in resource exhaustion and corruption of encrypted index data.

Affected products (as reported)

Vendor	Product	Versions
MongoDB	MongoDB Server	8.3.0 – before 8.3.88.0 – before 8.0.29

Weakness: CWE-191 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H

References

https://jira.mongodb.org/browse/SERVER-130628