Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 Mattermost fail to apply allocation limits to the byte-string decode paths in its WebSocket msgpack decoder, which allows an authenticated remote attacker to cause excessive server memory allocation via a crafted binary WebSocket frame declaring a Bin32 payload length of up to 4,294,967,295 bytes.. Mattermost Advisory ID: MMSA-2026-00768
References
History

Mon, 26 Oct 2026 17:45:00 +0000

Type Values Removed Values Added
First Time appeared Mattermost
Mattermost mattermost
Vendors & Products Mattermost
Mattermost mattermost

Mon, 26 Oct 2026 17:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Mon, 26 Oct 2026 15:00:00 +0000

Type Values Removed Values Added
Description Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 Mattermost fail to apply allocation limits to the byte-string decode paths in its WebSocket msgpack decoder, which allows an authenticated remote attacker to cause excessive server memory allocation via a crafted binary WebSocket frame declaring a Bin32 payload length of up to 4,294,967,295 bytes.. Mattermost Advisory ID: MMSA-2026-00768
Title Mattermost allows authenticated users to trigger excessive memory allocation via crafted msgpack binary WebSocket frames
Weaknesses CWE-789
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: Mattermost

Published: 2026-10-26T14:25:26.554Z

Updated: 2026-10-26T16:46:45.736Z

Reserved: 2026-09-18T18:40:09.913Z

Link: CVE-2026-93849

cve-icon Vulnrichment

Updated: 2026-10-26T16:40:48.739Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-10-26T15:16:46.367

Modified: 2026-10-26T17:17:31.240

Link: CVE-2026-93849

cve-icon Redhat

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