Legal Hold Plugin Vulnerability in Mattermost by Mattermost
CVE-2026-3524

8.3HIGH

Key Information:

Vendor

Mattermost
Status
Mattermost
Vendor
CVE Published:
6 April 2026

What is CVE-2026-3524?

The Mattermost Plugin Legal Hold versions up to 1.1.4 contain a vulnerability that fails to terminate request processing following a failed authorization check. This flaw exposes sensitive legal hold data, allowing authenticated attackers to exploit the plugin's endpoints through specially crafted API requests. Successful exploitation can lead to unauthorized access, creation, download, and deletion of vital legal hold data, thereby compromising data confidentiality and integrity.

Affected Version(s)

Mattermost 0 <= 1.1.4

Mattermost 1.1.5

References

https://mattermost.com/security-updates
vendor-advisory

CVSS V3.1

Score:
8.3
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Hassan Mohammed
.