CVE-2026-2454 MEDIUM

CVE-2026-2454: DoS in Calls plugin via malformed msgpack in websocket request.

Vendor Mattermost
Product Mattermost
Weakness CWE-1287
Published March 16, 2026
Last update March 17, 2026
View on NVD All CVEs

CVSS base score

5.8/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L

What the vulnerability does

01Description

Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to handle incorrectly reported array lengths which allows malicious user to cause OOM errors and crash the server via sending corrupted msgpack frames within websocket messages to calls plugin. Mattermost Advisory ID: MMSA-2025-00537

Key dates

02Disclosure timeline

March 16, 2026 CVE published
March 17, 2026 Record updated