CVE-2026-14298 PUBLISHED

Denial of service via resource exhaustion in Mattermost

Assigner: Mattermost
Reserved: 01.07.2026 Published: 13.08.2026 Updated: 13.08.2026

Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to properly limit resource consumption when processing certain user-supplied input, which allows an authenticated user to cause a denial of service. Mattermost Advisory ID: MMSA-2026-00713

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: 6.5

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 11.9.0 to 11.9.0 (incl.) affected from 11.8.0 to 11.8.4 (incl.) affected from 11.7.0 to 11.7.7 (incl.) affected from 10.11.0 to 10.11.22 (incl.) Version 11.10.0 is unaffected Version 11.9.1 is unaffected Version 11.8.5 is unaffected Version 11.7.8 is unaffected Version 10.11.23 is unaffected

Solutions

Update Mattermost to versions 11.10.0, 11.9.1, 11.8.5, 11.7.8, 10.11.23 or higher.

Credits

Edgar Bellot Micó finder

References

MMSA-2026-00713

Problem Types

CWE-409: Improper Handling of Highly Compressed Data (Data Amplification) CWE