Use-after-free in MongoDB Server - CVE-2026-8201
Published: August 18, 2026
Vulnerability identifier: #VU144155
CSH Severity: Low
CVSS v4: 6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-8201
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to cause a denial of service and disclose sensitive information.
The vulnerability exists due to use-after-free in the Field-Level Encryption (FLE) query analysis component when processing positional projections on encrypted fields in FLE-related queries. A remote user can send a specially crafted FLE-related query to cause a denial of service and disclose sensitive information.
The issue affects client-side uses of mongocryptd and crypt_shared, and exploitation requires control over the structure of a client's FLE-related query.
Affected software
MongoDB Server
How to mitigate CVE-2026-8201
Install security update from vendor's website.
MongoDB Server - addressed in versions 7.0.34, 8.0.23, 8.2.9, 8.3.2