High severity · published Aug 11, 2026
CVE-2026-18687
Improper Validation in MongoDB Queryable Encryption Maintenance Operation Leads to Denial of Service and Index Corruption
7.1
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
Low
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 14% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MO
MongoDB · MongoDB
8.3.0 before 8.3.8; 8.0 before 8.0.29 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-18687
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-18687
Vendor Advisory
https://jira.mongodb.org/browse/SERVER-130628
More from MongoDB
9.9
CVE-2019-10758
MongoDB mongo-express Remote Code Execution Vulnerability
7.5
CVE-2025-14847
Zlib compressed protocol header length confusion may allow memory read
9.8
CVE-2026-19001
MongoDB BI Connector ODBC driver may write outside an allocated buffer when handling oversized catalog object names
9.8
CVE-2025-3085
A MongoDB server under specific conditions running on Linux with TLS and CRL revocation status checking enabled, fails to check the revocation status of the intermediate…
9.8
CVE-2024-8654
MongoDB Server may access non-initialized region of memory leading to unexpected behaviour