CVE-2026-9602 PUBLISHED

Mattermost Desktop App crashes when malformed arguments are provided to some exposed IPC methods

Assigner: Mattermost
Reserved: 26.05.2026 Published: 17.07.2026 Updated: 17.07.2026

Mattermost Desktop App versions <=6.2 6.0.2 5.6.13.0 fail to validate payloads sent from the Mattermost Web App to the Desktop App which allows a malicious server owner to crash the Mattermost Desktop App via changing the payload of a method to a malformed one. Mattermost Advisory ID: MMSA-2026-00678

Metrics

CVSS 3.1

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CVSS Score: 5.7

Attack Vector	Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	None
Privileges Required	Low	Integrity Impact	None
User Interaction	None	Availability Impact	High

CVSS 3.1

Product Status

Vendor	Mattermost
Product	Mattermost
Versions	Default: unaffected affected from 0 to 6.0.2 (incl.) affected from 0 to 5.6.13 (incl.) Version 6.3.0 is unaffected Version 6.2.1.0 is unaffected Version 5.13.7.0 is unaffected

Solutions

Update Mattermost Desktop App to versions 6.3.0, 6.2.1.0, 5.13.7.0 or higher.

Credits

game0v3r finder

References

MMSA-2026-00678

Problem Types

CWE-400 Uncontrolled Resource Consumption CWE