CVE-2026-8336 HIGH

CVE-2026-8336: Post-authentication use-after-free error in $_internalJsEmit and mapreduce commands

Vendor Mongodb, Inc.
Product MongoDB Server
Weakness CWE-416
Published May 13, 2026
Last update May 15, 2026

CVSS base score

7.7/10
Attack vector Network
Attack complexity High
Privileges required Low
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/AU:N/R:A/V:D/RE:M/U:Red

What the vulnerability does

01Description

After invoking $_internalJsEmit, which is not intended to be directly accessible, or mapreduce command’s map function in a certain way, an authenticated user can subsequently crash mongod when the server-side JavaScript engine (through $where, $function, mapreduce reduce stage, etc.) is used also in a specific way, resulting in a post-authentication denial-of-service. This issue impacts MongoDB Server v8.2 versions prior to 8.2.9 and v8.3 versions prior to 8.3.2.

Key dates

02Disclosure timeline

May 13, 2026 CVE published
May 15, 2026 Record updated