CVE-2026-2454

DoS in Calls plugin via malformed msgpack in websocket request.

State: Published
Severity: 5.8 Medium
Published: Mar 16, 2026
Updated: Mar 17, 2026
Reserved: Feb 13, 2026

Description

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

Scores

CVSS	Score	Vector	Source
3.1	5.8 Medium	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L	Mattermost

Weaknesses

CWE-1287 Improper Validation of Specified Type of Input

Affected Products

Product	Versions
MattermostMattermost	11.3.0 through 11.3.0Affected 11.2.0 through 11.2.2Affected 10.11.0 through 10.11.10Affected 11.4.0Not affected 11.3.1Not affected 11.2.3Not affected 10.11.11Not affected

References

MMSA-2025-00537vendor-advisory

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