Description
Mattermost Plugins versions <=2.3.1 fail to limit the request body size on the {{/lifecycle}} webhook endpoint which allows an authenticated attacker to cause memory exhaustion and denial of service via sending an oversized JSON payload. Mattermost Advisory ID: MMSA-2026-00610
Published: 2026-04-09
Score: 3.7 Low
EPSS: < 1% Very Low
KEV: No
Impact: Denial of Service
Action: Patch
AI Analysis

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Remediation

Vendor Solution

Update Mattermost Plugins to versions 2.3.2.0 or higher.

Tracking

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-x274-8qfc-hrgf Mattermost MS Teams plugin doesn't limit the request body size on the /lifecycle webhook endpoint
References
History

Sat, 25 Apr 2026 18:15:00 +0000

Type Values Removed Values Added
First Time appeared Mattermost mattermost Server
CPEs cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:* cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
Vendors & Products Mattermost mattermost Server

Fri, 17 Apr 2026 20:30:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:mattermost:mattermost:*:*:*:*:*:*:*:*

Fri, 10 Apr 2026 09:00:00 +0000

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

Thu, 09 Apr 2026 12:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

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


Thu, 09 Apr 2026 10:30:00 +0000

Type Values Removed Values Added
Description Mattermost Plugins versions <=2.3.1 fail to limit the request body size on the {{/lifecycle}} webhook endpoint which allows an authenticated attacker to cause memory exhaustion and denial of service via sending an oversized JSON payload. Mattermost Advisory ID: MMSA-2026-00610
Title Unbounded Request Body Read in MS Teams Plugin {{/lifecycle}} Webhook Endpoint
Weaknesses CWE-770
References
Metrics cvssV3_1

{'score': 3.7, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L'}


Subscriptions

Mattermost Mattermost Mattermost Server
cve-icon MITRE

Status: PUBLISHED

Assigner: Mattermost

Published:

Updated: 2026-04-09T11:44:54.614Z

Reserved: 2026-02-11T20:56:06.579Z

Link: CVE-2026-21388

cve-icon Vulnrichment

Updated: 2026-04-09T11:44:50.805Z

cve-icon NVD

Status : Analyzed

Published: 2026-04-09T11:16:20.897

Modified: 2026-04-25T18:02:06.810

Link: CVE-2026-21388

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-04-10T09:32:56Z

Weaknesses