CVE-2026-5308 - Vulnerability Details - OpenCVE

Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to enforce request body size limits on plugin HTTP endpoints which allows an attacker to cause a denial of service via crafted oversized HTTP requests.. Mattermost Advisory ID: MMSA-2026-00646

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required High

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00036.

Exploitation none

Automatable no

Technical Impact partial

Vendors	Products
Mattermost	Mattermost

No data.

No data.

OpenCVE Enrichment is a feature of OpenCVE that uses AI to automatically link vendors and products to CVEs. Learn more on GitHub.

Vendors	Products
Mattermost	Mattermost

References

Link	Providers
https://mattermost.com/security-updates

History

Fri, 22 May 2026 13:30:00 +0000

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Fri, 22 May 2026 12:45:00 +0000

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

Fri, 22 May 2026 11:00:00 +0000

Type	Values Removed	Values Added
Description		Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to enforce request body size limits on plugin HTTP endpoints which allows an attacker to cause a denial of service via crafted oversized HTTP requests.. Mattermost Advisory ID: MMSA-2026-00646
Title		Missing request body size limits on Zoom plugin HTTP endpoints
Weaknesses		CWE-400
References		https://mattermost.com/security-updates
Metrics		cvssV3_1 `{'score': 4.9, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H'}`

MITRE

Status: PUBLISHED

Assigner: Mattermost

Published: 2026-05-22T10:20:43.629Z

Updated: 2026-05-22T12:14:58.221Z

Reserved: 2026-04-01T10:35:26.431Z

Link: CVE-2026-5308

Vulnrichment

Updated: 2026-05-22T12:14:55.248Z

NVD

No data.

Redhat

No data.

OpenCVE Enrichment

Updated: 2026-05-22T13:00:13Z

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