Mattermost Plugin Legal Hold <=1.1.4 Auth Bypass in ServeHTTP
CVE-2026-3524 Published on April 6, 2026

Authorization Bypass in Mattermost Legal Hold Plugin Due to Missing Return After Permission Check
Mattermost Plugin Legal Hold versions <=1.1.4 fail to halt request processing after a failed authorization check in ServeHTTP which allows an authenticated attacker to access, create, download, and delete legal hold data via crafted API requests to the plugin's endpoints. Mattermost Advisory ID: MMSA-2026-00621

Vendor Advisory NVD

Vulnerability Analysis

CVE-2026-3524 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 be very high.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
LOW
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH

Weakness Type

What is an AuthZ Vulnerability?

The software does not perform an authorization check when an actor attempts to access a resource or perform an action.

CVE-2026-3524 has been classified to as an AuthZ vulnerability or weakness.


Products Associated with CVE-2026-3524

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MatterMost
 

Affected Versions

Mattermost:

Exploit Probability

EPSS
0.01%
Percentile
2.72%

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.