CVE-2026-5308 PUBLISHED

Missing request body size limits on Zoom plugin HTTP endpoints

Assigner: Mattermost
Reserved: 01.04.2026 Published: 22.05.2026 Updated: 22.05.2026

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

Metrics

CVSS 3.1

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
CVSS Score: 4.9

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

CVSS 3.1

Product Status

Vendor	Mattermost
Product	Mattermost
Versions	Default: unaffected affected from 11.6.0 to 11.6.0 (incl.) affected from 11.5.0 to 11.5.3 (incl.) affected from 11.4.0 to 11.4.4 (incl.) affected from 10.11.0 to 10.11.14 (incl.) Version 11.7.0 is unaffected Version 11.6.1 is unaffected Version 11.5.4 is unaffected Version 11.4.5 is unaffected Version 10.11.15 is unaffected

Solutions

Update Mattermost to versions 11.7.0, 11.6.1, 11.5.4, 11.4.5, 10.11.15 or higher.

Credits

thecybertantrik finder

References

MMSA-2026-00646

Problem Types

CWE-400 Uncontrolled Resource Consumption CWE