MongoDB Change Streams Privilege Bypass Data Leakage
CVE-2026-120816 Published on November 10, 2026

System collection contents readable through a database change stream with showSystemEvents
A user with basic read-tier database privileges can use an option on a server-side data-change notification feature to receive the contents of certain restricted internal collections that the same user is refused on a direct read. The privilege check for the notification feature is derived only from the target namespace and does not account for the option, so no additional permission is required. This may result in unintended access to data stored in those internal collections.

NVD

Vulnerability Analysis

CVE-2026-120816 is exploitable with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity and availability.

Exploitation:
NONE
Automatable:
NO
Technical Impact:
PARTIAL
Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
LOW
User Interaction:
NONE

Weakness Type

What is an AuthZ Vulnerability?

The software performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. This allows attackers to bypass intended access restrictions.

CVE-2026-120816 has been classified to as an AuthZ vulnerability or weakness.


Products Associated with CVE-2026-120816

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Affected Versions

MongoDB Server:

Exploit Probability

EPSS
0.27%
Percentile
19.36%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.